Process for preparation of sulfonyl carbamate bile acid derivatives

ABSTRACT

The present invention relates to processes for preparing compounds of Formula (I) and Formula (II): 
     
       
         
         
             
             
         
       
     
     These compounds are useful as FXR or TGR5 modulators. The present invention also relates to processes for the preparation of the compounds of Formula (III), Formula (IV), Formula (V), and Formula (VI), 
     
       
         
         
             
             
         
       
     
     The present invention also relates to a process for the preparation of compounds (VII), (VIII) and (IX),

RELATED APPLICATIONS

This application is a continuation application of U.S. application Ser.No. 15/948,370, filed on Apr. 9, 2018, which claims the benefit of U.S.Provisional Application No. 62/483,044, filed on Apr. 7, 2017. Theentire teachings of the above applications are incorporated herein byreference.

TECHNICAL FIELD

The present invention relates to processes and intermediates useful inthe preparation of biologically active molecules useful as FXR or TGR5modulators, especially relates to bile acid derivatives and methods fortheir preparation and use.

BACKGROUND OF THE INVENTION

Farnesoid X Receptor (FXR) is an orphan nuclear receptor initiallyidentified from a rat liver cDNA library (BM. Forman, et al., Cell,1995, 81(5), 687-693) that is most closely related to the insectecdysone receptor. FXR is a member of the nuclear receptor family ofligand-activated transcription factors that includes receptors for thesteroid, retinoid, and thyroid hormones (DJ. Mangelsdorf, et al., Cell,1995, 83(6), 841-850). The relevant physiological ligands of FXR arebile acids (D. Parks et al., Science, 1999, 284(5418), 1362-1365). Themost potent one is chenodeoxycholic acid (CDCA), which regulates theexpression of several genes that participate in bile acid homeostasis.Farnesol and derivatives, together called farnesoids, are originallydescribed to activate the rat orthologue at high concentration but theydo not activate the human or mouse receptor. FXR is expressed in theliver, throughout the entire gastrointestinal tract including theesophagus, stomach, duodenum, small intestine, colon, ovary, adrenalgland and kidney. Beyond controlling intracellular gene expression, FXRseems to be also involved in paracrine and endocrine signaling byupregulating the expression of the cytokine Fibroblast Growth Factor (J.Holt et al., Genes Dev., 2003, 17(13), 1581-1591; T. Inagaki et al.,Cell Metab., 2005, 2(4), 217-225).

Small molecule compounds which act as FXR modulators have been disclosedin the following publications: WO 2000/037077, WO 2002/072598, WO2003/015771, WO 2003/099821, WO 2004/00752, WO 2004/048349, WO2005/009387, WO 2005/082925, US 2005/0054634, WO 2007/052843, WO2007/070796, WO 2007/076260, WO 2007/092751, WO 2007/095174, WO2007/140174, WO 2007/140183, US 2007/0142340, WO 2008/000643, WO2008/002573, WO 2008/025539, WO 2008/025540, WO 2008/051942, WO2008/073825, WO 2008/157270, US 2008/0299118, US 2008/0300235, WO2009/005998, WO 2009/012125, WO 2009/027264, WO 2009/062874, WO2009/127321, WO 2009/149795, US 2009/0131409, US 2009/0137554, US2009/0163474, US 2009/0163552, US 2009/0215748, WO 2010/043513, WO2011/020615, WO 2011/117163, WO 2012/087519, WO 2012/087520, WO2012/087521, WO 2013/007387, WO 2013/037482, WO 2013/166176, WO2013/192097, WO 2014/184271, US 2014/0186438, US 2014/0187633, WO2015/017813, WO 2015/069666, WO 2016/073767, WO 2016/116054, WO2016/103037, WO 2016/096116, WO 2016/096115, WO 2016/097933, WO2016/081918, WO 2016/127924, WO 2016/130809, WO 2016/145295, WO2016/173524, CN 106632294, CN 106588804, US 2017/0196893, WO2017/062763, WO 2017/053826, CN 106518708, CN 106518946, CN 106478759,CN 106478447, CN 106478453, WO 2017/027396, WO 2017/049172, WO2017/049173, WO 2017/049176, WO 2017/049177, WO 2017/118294, WO2017/128896, WO 2017/129125, WO 2017/133521, WO 2017/147074, WO2017/147174, WO 2017/145041, and WO 2017/156024 A1.

Further small molecule FXR modulators have been recently reviewed (R. C.Buijsman et al. Curr. Med. Chem. 2005, 12, 1017-1075).

TGR5 receptor is a G-protein-coupled receptor that has been identifiedas a cell-surface receptor that is responsive to bile acids (BAs). Theprimary structure of TGR5 and its responsiveness to bile acids has beenfound to be highly conserved in TGR5 among human, bovine, rabbit, rat,and mouse, and thus suggests that TGR5 has important physiologicalfunctions. TGR5 has been found to be widely distributed in not onlylymphoid tissues but also in other tissues. High levels of TGR5 mRNAhave been detected in placenta, spleen, and monocytes/macrophages. Bileacids have been shown to induce internalization of the TGR5 fusionprotein from the cell membrane to the cytoplasm (Kawamata et al., J Bio.Chem., 2003, 278, 9435). TGR5 has been found to be identical to hGPCR19reported by Takeda et al., FEBS Lett. 2002, 520, 97-101.

TGR5 is associated with the intracellular accumulation of cAMP, which iswidely expressed in diverse cell types. While the activation of thismembrane receptor in macrophages decreases pro-inflammatory cytokineproduction, (Kawamata, Y., et al., J. Biol. Chem. 2003, 278, 9435-9440)the stimulation of TGR5 by BAs in adipocytes and myocytes enhancesenergy expenditure (Watanabe, M., et al. Nature. 2006, 439, 484-489).This latter effect involves the cAMP-dependent induction of type 2iodothyronine deiodinase (D2), which by, locally converting T4 into T3,gives rise to increased thyroid hormone activity. Consistent with therole of TGR5 in the control of energy metabolism, female TGR5 knock-outmice show a significant fat accumulation with body weight gain whenchallenged with a high fat diet, indicating that the lack of TGR5decreases energy expenditure and elicits obesity (Maruyama, T., et al.,J. Endocrinol. 2006, 191, 197-205). In addition and in line with theinvolvement of TGR5 in energy homeostasis, bile acid activation of themembrane receptor has also been reported to promote the production ofglucagon-like peptide 1 (GLP-1) in murine enteroendocrine cell lines(Katsuma, S., Biochem. Biophys. Res. Commun., 2005, 329, 386-390). Onthe basis of all the above observations, TGR5 is an attractive targetfor the treatment of disease e.g., obesity, diabetes and metabolicsyndrome.

In addition to the use of TGR5 agonists for the treatment and preventionof metabolic diseases, compounds that modulate TGR5 modulators are alsouseful for the treatment of other diseases e.g., central nervousdiseases as well as inflammatory diseases (WO 01/77325 and WO 02/84286).Modulators of TGR5 also provide methods of regulating bile acid andcholesterol homeostasis, fatty acid absorption, and protein andcarbohydrate digestion.

There is a need for the development of FXR and/or TGR5 modulators forthe treatment and prevention of disease.

SUMMARY OF THE INVENTION

The present invention relates to processes for preparing compounds ofFormula (I) and compounds of Formula (II):

or a pharmaceutically acceptable salt thereof, wherein

R¹ is selected from the group consisting of:

-   -   1) substituted or unsubstituted —C₁-C₈ alkyl;    -   2) substituted or unsubstituted —C₂-C₈ alkenyl;    -   3) substituted or unsubstituted —C₂-C₈ alkynyl;    -   4) substituted or unsubstituted —C₃-C₈ cycloalkyl;    -   5) substituted or unsubstituted aryl;    -   6) substituted or unsubstituted arylalkyl;    -   7) substituted or unsubstituted 3- to 12-membered        heterocycloalkyl;    -   8) substituted or unsubstituted heteroaryl;    -   9) substituted or unsubstituted heteroarylalkyl; and    -   10) NR_(a)R_(b); wherein, R_(a) and R_(b) are each independently        selected from hydrogen, substituted or unsubstituted —C₁-C₈        alkyl, substituted or unsubstituted —C₂-C₈ alkenyl, substituted        or unsubstituted —C₂-C₈ alkynyl, substituted or unsubstituted        —C₃-C₈ cycloalkyl. Alternatively R_(a) and R_(b) are taken        together with the nitrogen atom to which they attached to form a        3- to 12-remembered heterocyclic ring.

A preferred embodiment of a compound of Formula (I) is compound (VII):

A preferred embodiment of a compound of Formula (II) is compound (VIII):

Another preferred embodiment of a compound of Formula (II) is compound(X):

In certain embodiments, the present invention relates to methods ofpreparing the compound of Formula (III) which is an intermediate in thesynthesis of compounds of Formula (I) and Formula (II).

wherein PG is a hydroxyl protecting group such as, but not limited to,acetyl, THP, MOM, MEM, SEM, or a silyl group, such as TBS, TES, TMS,TIPS, or TBDPS. Preferably PG is TBS.

In certain embodiments, the present invention relates to methods ofpreparing a compound of Formula (IV) which is an intermediate in thesynthesis of compounds of Formula (I).

In certain embodiments, the present invention relates to methods ofpreparing the compound of Formula (V) which is an intermediate in thesynthesis of compounds of Formula (II).

In certain embodiments, the present invention relates to methods ofpreparing the compound of Formula (VI) which is a useful intermediate inthe synthesis of compounds of Formula (II).

In one embodiment, the process for preparing a compound of Formula (I)comprises the steps of:

1(a) converting compound 1 (CDCA) to the compound of Formula (III)

2(a) converting the compound of Formula (III) to the compound of Formula(IV)

3(a) converting the compound of Formula (IV) to the compound of Formula(I)

wherein PG, and R¹ is as previously defined.

In one embodiment, the process for preparing a compound of Formula (II)comprises the steps of:

1(a) converting compound 1 (CDCA) to the compound of Formula (III)

2(b) converting the compound of Formula (III) to the compound of Formula(V)

3(b) converting the compound of Formula (V) to the compound of Formula(VI)

4(b) converting the compound of Formula (VI) to the compound of Formula(II)

wherein PG and R¹ are as previously defined.

The invention further relates to methods for increasing product yieldand decreasing process steps for intermediate and large scale productionof compounds of Formula (I), Formula (II), Formula (III), Formula (IV),Formula (V), and Formula (VI).

The compounds of Formula (I), Formula (II), compound (VII), compound(VIII) and compound (IX) are useful for the treatment of a chronic liverdisease, such as a disease selected from the group consisting of primarybiliary cirrhosis (PBC), cerebrotendinous xanthomatosis (CTX), primarysclerosing cholangitis (PSC), drug induced cholestasis, intrahepaticcholestasis of pregnancy, parenteral nutrition associated cholestasis(PNAC), bacterial overgrowth or sepsis associated cholestasis,autoimmune hepatitis, chronic viral hepatitis, alcoholic liver disease,nonalcoholic fatty liver disease (NAFLD), nonalcoholic steatohepatitis(NASH), liver transplant associated graft versus host disease, livingdonor transplant liver regeneration, congenital hepatic fibrosis,choledocholithiasis, granulomatous liver disease, intra- or extrahepaticmalignancy, Sjögren's syndrome, Sarcoidosis, Wilson's disease, Gaucher'sdisease, hemochromatosis, and alpha 1-antitrypsin deficiency(WO2016/086218A1).

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to processes for preparing compounds ofFormula (I) and compound of Formula (II)

or a pharmaceutically acceptable salt, wherein R¹ is as previouslydefined.

In certain embodiments, the present invention relates to processes forpreparing compounds of Formula (I) and compounds of Formula (II), andpharmaceutically acceptable salts thereof, wherein R¹ is substituted orunsubstituted aryl; substituted or unsubstituted heteroaryl; substitutedor unsubstituted 3- to 12-membered heterocycloalkyl.

In certain embodiments, the present invention relates to processes forpreparing compounds of Formula (I) and compounds of Formula (II), andpharmaceutically acceptable salts thereof, wherein R¹ is substituted orunsubstituted phenyl; or substituted or unsubstituted pyridyl.

In certain embodiments, the present invention relates to processes forpreparing compounds of Formula (I) and compounds of Formula II), andpharmaceutically acceptable salts thereof, wherein R¹ is substituted orunsubstituted

or substituted or unsubstituted

In another embodiment, the present invention relates to processes forpreparing compound (VII).

In another embodiment, the present invention relates to processes forpreparing compound (VIII).

In another embodiment, the present invention relates to the processesfor preparing compound (IX).

In one embodiment, step 1(a) is set forth in scheme 1. The methodcomprises steps 1(a)(i): esterifying chenodeoxycholic acid (CDCA,compound 1) with a C₁-C₆-alkanol, preferably methanol or ethanol, morepreferably methanol, to produce compound 2; 1(a)(ii): reacting compound2 with a strong base in the presence of a suitable hydroxyl protectingagent and an electrophilic halogen source to produce compound 3;1(a)(iii): eliminating the R² group in compound 3 to produce compound 4;1(a)(iv): deprotecting compound 4 to produce compound 5; 1(a)(v):protecting compound 5 to produce compound 6; and 1(a)(vi): oxidativelycleaving and oxidizing compound 6 to produce compound (III).

wherein PG is previously defined; PG¹ is a hydroxyl protecting grouppreferably selected from silyl groups, such as, but not limited to, TMS,TES, TBS, TIPS, and TBDPS; and R² is selected from Cl, Br, and I. Thepreferred PG¹ is TMS. The preferred PG is TBS. R⁶ is C₁-C₆-alkyl,preferably methyl or ethyl and more preferably methyl.

Step 2(a) is conducted as set forth in scheme 2. Thus, in step 2(a)(i)the compound (III) reacts with chloroformate reagent R₃OC(O)C1 toproduce anhydride compound 7, followed by step 2(a)(ii), reducingcompound 7 to produce compound (IV).

wherein PG was previously defined; R³ is an alkyl group, preferablyC₁-C₆-alkyl, such as, but not limited to, methyl, ethyl, isopropyl orisobutyl. The preferred R³ is isobutyl.

The present invention will be better understood in connection with Steps1(a)(i)-1(a)(vi) and 2(a)(i)-2(a)(ii), wherein PG, PG¹, R², and R³ areas previously defined unless otherwise indicated. It will be readilyapparent to one of ordinary skill in the art that the process of thepresent invention can be practiced by substitution of the appropriatereactants and that the order of the steps themselves can be varied.

Step 1(a)(i), Converting Compound 1 to Compound 2:

Step 1(a)(i) is the esterification of CDCA with an alkyl alcohol,preferably a C₁-C₆-alkanol, and more preferably methanol as is known inthe art, for example the procedures described in Tetrahedron, 57(8),1449-1481; 2001.

Step 1(a)(ii), Converting Compound 2 to Compound 3:

Step 1(a)(ii) is the conversion of compound 2 to compound 3 viahalogenation of an intermediate silyl ketene acetal 2a. The silyl keteneacetal intermediate 2a is directly generated in situ by reactingcompound 2 with a strong base, such as, but not limited to, LDA in thepresence of a suitable hydroxyl protecting agent PG¹-X, wherein X isselected from Cl, Br, I, and OTf. The preferred hydroxyl protectingagent is TMS-Cl. In one aspect, the temperature is from −100° C. to −50°C. In one aspect, the temperature is from −90° C. to −60° C. In oneaspect, the temperature is from −80 to −70° C. The silyl ketene acetalintermediate 2a reacts with an electrophilic halogenating reagent, suchas, but not limited to, Br₂, I₂, I—Cl, I—Br, NBS, NIS, and1,3-dibromo-5,5-dimethylhydantoin to give compound 3. The preferredelectrophilic halogenating reagent is I₂.Step 1(a)(iii), Converting Compound 3 to Compound 4:

Step 1(a)(iii) is the elimination of H—R² from compound 3 to formcompound 4. Compound 3 is treated with a suitable organic base, such as,but not limited to, DIPEA, Et₃N, DBU, DBN, or DABCO, in a solvent orsolvent mixture such as, but not limited to, THF, DCM, acetonitrile, ortoluene. The preferred organic base is DBU. In a preferred aspect, thesolvent is THF. In a preferred aspect, compound 3 from Step 1(a)(ii) isused directly without further purification. The reaction can be carriedout at a temperature ranging from −10° C. to 50° C. In a preferredaspect, the reaction temperature is from 0° C. to 30° C. In anotherpreferred aspect, the reaction temperature is about 25° C.

Step 1(a)(iv), Converting Compound 4 to Compound 5:

Step 1(a)(iv) is the removal of the protecting group, PG¹ of compound 4to form compound 5. The protecting group can be removed under suitabledeprotection conditions as are known in the art. For example, PG¹ can beremoved by a deprotecting reagent such as, but not limited to, TBAF, oran acid such as HCl. Preferably compound 4 is treated with an acid in anaprotic solvent. In a preferred aspect of Step 1(a)(iv), compound 4 fromStep 1(a)(iii) is used directly without further purification. Preferablycompound 4 is treated with an acid, such as HCl, in an aprotic solventsuch as, but not limited to, THF, 1,4-dioxane, MTBE, Et₂O, or a mixtureof two. The preferred solvent is 1,4-dioxane. The reaction can becarried out at a temperature ranging from −10° C. to 50° C. In apreferred aspect, the reaction temperature is from 0° C. to 30° C. Inanother preferred aspect, the reaction temperature is about 25° C. Inyet another preferred aspect, compound 4 is treated with HCl in1,4-dioxane at room temperature to give compound 5. Compound 5 can bepurified by column chromatography to provide compound 5. The overallyield for the conversion of compound 1 to compound 5 is greater than 60%after the purification of compound 5.

Step 1(a)(v), Converting Compound 5 to Compound 6:

Step 1(a)(v) is the protection of the 3-hydroxyl of compound 5 with asuitable hydroxyl protecting agent PG-X, wherein X is a suitable leavinggroup, preferably Cl, Br, I, or OTf, in the presence of an organic basesuch as, but not limited to, imidazole, TEA, DIPEA to produce compound6. The preferred hydroxyl protecting agent is TBS-Cl. The preferredorganic base is imidazole. The reaction can be carried out at atemperature ranging from −10° C. to 50° C. In a preferred aspect, thereaction temperature is from 0° C. to 30° C. In another preferredaspect, the reaction temperature is about 25° C.

Step 1(a)(vi), Converting Compound 6 to Compound III:

Step 1(a)(vi) is dihydroxylation, oxidative cleavage, and 7-OH oxidationof compound 6 with a suitable catalyst such as, but not limited to,RuCl₃ in the presence of a stoichiometric oxidant such as, but notlimited to, NaIO₄, n-Bu₄N⁺IO₄ ⁻, and NMO to produce compound (III). Thereaction is conducted in the presence of a suitable base such as, butnot limited to, K₂CO₃, Na₂CO₃, and 2,6-lutidine. The preferred oxidantis NaIO₄. The preferred base is K₂CO₃. The reaction is carried out in asolvent such as, but not limited to, H₂O, CCl₄, CH₃CN or EtOAc. Thepreferred solvent is a mixture of H₂O, CH₃CN, and EtOAc. The reactioncan be carried out at a temperature ranging from −10° C. to 50° C. In apreferred aspect, the reaction temperature is from 0° C. to 30° C. Inanother preferred aspect, the reaction temperature is about 25° C.Compound (III) can be crystallized from organic solvent or solventmixture such as, but not limited to, hexanes/EtOAc to provide compound(III) with purity greater than 95%.

Step 2(a)(i), Converting Compound (III) to Compound 7:

Step 2(a)(i) is the reaction of compound (III) with chloroformateR³OCOCl in the presence of an organic base such as, but not limited to,TEA or DIPEA to produce mixed anhydride 7. Step 2(a)(i) is preferablyconducted in an aprotic solvent such as, but not limited to, DCM. Thepreferred chloroformate is isobutyl chloroformate, wherein R³ isisobutyl. The preferred organic base is TEA. Compound 7 is isolated andused for next step reaction without purification.

Step 2(a)(ii), Converting Compound 7 to Compound (IV):

Step 2(a)(ii) is the reaction of compound 7 with a suitable reducingagent such as, but not limited to, NaBH₄, LiBH₄, LiAlH₄, or DIBAL toproduce compound (IV). Step 2(a)(ii) is preferably carried out in amixture of a protic and non-protic solvent, such as, but not limited toa mixture of water and THF. The reaction can be carried out at atemperature ranging from −10° C. to 50° C. In a preferred aspect, thereaction temperature is from 0° C. to 30° C. In another preferredaspect, the reaction temperature is about 25° C.

In one embodiment, Step 2(b) is conducted as set forth in scheme 3. Themethod comprises the steps of 2(b)(i): the simultaneous TBS deprotectionand esterification of compound (III) to produce compound 8; 2(b)(ii):reacting compound 8 with a strong base in the presence of a suitablehydroxyl protecting agent to produce enol ether compound 9; 2(b)(iii):reacting compound 9 with acetaldehyde to produce compound 10; 2(b)(iv):hydrogenating compound 10 to produce compound 11; 2(b)(v): reactingcompound 11 with base in a protic solvent or a mixture of a proticsolvent and a non-protic solvent to produce compound (12); and 2(b)(vi):protecting compound 12 to produce compound (V).

wherein PG is as previously defined; PG³ is a hydroxy protecting groupselected from silyl groups, such as, but not limited to, TMS, TES, TBS,TIPS, and TBDPS. The preferred PG³ is TMS. R₆ is as previously defined.

The present invention will be better understood in connection with Steps2(b)(i) to 2(b)(vi), wherein PG, PG³ and R³ are as previously definedunless otherwise indicated. It will be readily apparent to one ofordinary skill in the art that the process of the present invention canbe practiced by substitution of the appropriate reactants and that theorder of the steps themselves can be varied.

Step 2(b)(i), Converting Compound (III) to Compound 8:

Step 2(b)(i) is the esterification and removal of the PG protectinggroup of compound (III) to form compound 8. The preferred protectinggroup is TBS. The protecting group can be removed under suitabledeprotection conditions as are known in the art. For example, theprotecting group can be removed by a deprotecting reagent such as, butnot limited to, an acid such as HCl. Preferably compound (III) istreated with an acid in a C₁-C₆-alkanol, preferably MeOH or EtOH, morepreferably MeOH. The reaction can be carried out at a temperatureranging from 25° C. to 100° C. In a preferred aspect, the reactiontemperature is from 35° C. to 80° C. In another preferred aspect, thereaction temperature is about 50° C. Compound 8 can be purified byrecrystallization to provide compound 8 with purity greater than 95%.

Step 2(b)(ii), Converting Compound 8 to Compound 9:

Step 2(b)(ii) is the formation of the silyl ether compound 9 by reactingcompound 8 with a silylating agent in the presence of a base in anaprotic solvent, such as, but not limited to DCM and TIF.

In one aspect of Step 2(b)(ii), the silylating agent is TMSCl, and thebase is a strong organic base such as, but not limited to, NaHMIDS,LiMIDS or LDA, and the reaction occurs at a lower temperature, such asabout −78° C.

In another preferred aspect of Step 2(b)(ii), the silylating agent isTMSOTf and is used together with an organic base such as, but notlimited to, TEA or DIPEA at a reaction temperature ranging from −20° C.to 30° C. In a preferred aspect, the reaction temperature is from about−5° C. to about 15° C. In another aspect, the temperature is about 0° C.The molar ratio of TMSOTf to compound 8, preferably ranges from 3 to 12.In one aspect, the molar ratio is 3 to 6. In one aspect, the molar ratiois 4.5 to 5.5.

In a preferred aspect, compound 9 can be used directly in Step 2(b)(iii)without purification.

Prior to conducting Step 2(b)(iii), it is preferred to remove theresidual water in the crude compound 9 from Step 2(b)(ii) to control thedecomposition of compound 9. In one aspect, compound 9 produced in Step2(b)(ii) is dissolved in an aprotic solvent, such as, but not limitedto, DCM, heptane, hexanes, or toluene, and is washed extensively withwater to remove trace amount of the base. The water content is limitedto <0.5% (Karl Fisher titration) by co-distillation with an anhydrousaprotic solvent, such as DCM, hexane, heptane, toluene, or THF.

Step 2(b)(iii), Converting Compound 9 to Compound 10:

Step 2(b)(iii) is an aldol reaction of compound 9 with acetaldehyde toproduce intermediate compound 9a, followed by elimination to formcompound 10 in the presence of a Lewis acid, such as, but not limitedto, BF₃.Et₂O or Ti(OiPr)₄. In one aspect of Step 2(b)(iii), the Lewisacid is BF₃.Et₂O. The reaction is carried out in an aprotic solvent,such as, but not limited to, DCM. The reaction temperature is preferablyfrom about −78° C. to 25° C. In one aspect, the reaction temperature isfrom about −78° C. to about −50° C. In another preferred aspect, thereaction temperature is about −60° C.

Following the reaction of compound 9 with acetaldehyde at about −78° C.to about −50° C. (step 2(b)(iii)(a)), the aldol product compound 9a isformed initially as the major product. Methanol is then added to thereaction mixture to quench the reaction and facilitate the eliminationto form the olefin compound 10 (step 2(b)(iii)(b). Alternatively thereaction is allowed to proceed at a higher temperature, such as from−10° C. to room temperature, without the addition of methanol tofacilitate the olefin formation to provide compound 10.

In one aspect of Step 2(b)(iii), compound 10 is a mixture of E- andZ-olefin isomers as illustrated by the structures of compound 10A below.The E/Z ratio can be 1/1 to >9/1.

Compound 10 can be purified by column chromatography to provide compound10 with purity greater than 95%. In a preferred aspect, compound 10 canbe used directly in Step 2(b)(iv) without purification.

In one aspect of Step 2(b)(iii), E-isomer compound 10 is obtained as thedominant isomer (E-isomer 10 is greater than 80% and Z-isomer is lessthan 20%). In another aspect, the E-isomer is greater than 90% andZ-isomer is less than 10%. In another aspect, the E-isomer is greaterthan 95% and Z-isomer is less than 5%.

In one aspect of Step 2(b)(iii), the crude product 10 contains less than5% of ketone compound 8. In another aspect, the crude product 10contains less than 3% of ketone compound 8. In another aspect, the crudeproduct 10 contains less than 2% of ketone compound 8.

Step 2(b)(iv), Converting Compound 10 to Compound 11:

In Step 2(b)(iv), compound 10 from Step 2(b)(iii) is converted tocompound 11 via a catalytic hydrogenation to reduce the olefin. In oneaspect of Step 2(b)(iv), compound 10 from Step 2(b)(iii) has beenpurified via column chromatography. In a preferred aspect of Step2(b)(iv), the crude product 10 obtained after work-up of Step 2(b)(iii)is used directly without purification. In one aspect of Step 2(b)(iv),the crude product 10 contains both E- and Z olefin isomers (10A). Thepercentage of Z-isomer preferably ranges from 0% to 50%.

The catalytic hydrogenation is carried out in the presence of a catalystsuch as, but not limited to, palladium on carbon (Pd/C), Pd(OAc)₂,Pd(OH)₂ and PtO₂. The preferred catalyst is Pd/C. The palladium contentof this Pd/C can range from about 5% to about 10%. The amount ofcatalyst can be rang from about 1 mol % to about 10 mol %. The hydrogensource can be, but is not limited to, hydrogen gas and ammonium formate.The pressure of hydrogen gas preferably ranges from atmospheric pressureto about 500 psi. In one aspect of Step 2(b)(iv), the pressure ofhydrogen gas is atmospheric pressure. In one aspect, the pressure ofhydrogen gas is from about 50 to about 150 psi. The reaction temperaturepreferably ranges from about 5° C. to about 120° C. In one aspect, thereaction temperature is from about 5° C. to about 80° C. In one aspectof Step 2(b)(iv), the reaction temperature is from about 20° C. to about50° C. In one aspect, the reaction temperature is about 25° C. Thereaction can be conducted in a protic or aprotic solvent or mixture oftwo solvents. Suitable solvents include, but are not limited to,methanol, ethanol, isopropanol, tert-butanol, and TH. In one aspect ofStep 2(b)(iv), the solvent is a mixture of methanol and THF. In anotherone aspect of Step 2(b)(iv), ethanol and THE mixture is used as thesolvent.

In certain embodiments, compound 11 is produced as a mixture of the6α-ethyl isomer and the 6β-ethyl isomer. In certain embodiments, the6β-ethyl isomer is the dominant isomer in the product. In one aspect ofStep 2(b)(iv), the crude compound 11 contains less than 20% of 6α-ethylisomer. In one aspect of Step 2(b)(iv), the crude compound 11 containsless than 10% of 6α-ethyl isomer. In one aspect of Step 2(b)(iv), thecrude compound 11 contains less than 5% of 6α-ethyl isomer. Compound 11can be used directly in Step 2(b)(v) without purification.

Although compound 11 is shown above as the 6β-ethyl isomer, inembodiments in which the compound is a mixture of of the 6-alpha and6-beta-ethyl isomers, it can be represented as compound 11A below.

Step 2(b)(v), Converting Compound 11 to Compound 12:

Step 2(b)(v) is the epimerization of the 6β-ethyl isomer of compound 11to the 6α-ethyl isomer, compound 12, under basic conditions. In oneaspect of Step 2(b)(v), the crude product obtained from Step 2(b)(iv),which contains both 6β-ethyl isomer and 6α-isomer, is used in the Step2(b)(vi) without further purification.

The base can be, but is not limited to, sodium hydroxide or potassiumhydroxide. In one aspect, the base is an aqueous sodium hydroxidesolution. In one aspect of Step 2(b)(vi), the base is a 50% solution ofsodium hydroxide in water.

In one aspect of Step 2(b)(v), the crude product of Step 2(b)(iv) isdirectly used in Step 2(b)(v) after removal of the catalyst, such asPd/C, by filtration. In one aspect of Step 2(b)(v), the crude product 11is used after the removal of the catalyst and the solvent.

Step 2(b)(v) is preferably carried out in a protic solvent such as, butnot limited to methanol or ethanol, or a mixture of a protic andnon-protic solvent, such as, but not limited to a mixture of methanol orethanol and THF.

In one aspect of Step 2(b(v), the solvent is ethanol. In another aspectof Step 2(b)(v), the solvent is methanol. In another aspect of Step2(b)(v), the solvent is a mixture of ethanol and THF. In another aspectof Step 2(b)(v), the solvent is a mixture of methanol and THF. Compound12 can be used directly in Step 2(b)(vi) without purification.

Step 2(b)(vi), Converting Compound 12 to Compound (V):

Step 2(b)(vi) is the protection of the 3-hydroxyl and acid of compound12 with a suitable hydroxyl protecting agent PG-X, wherein X is asuitable leaving group, preferably Cl, Br, I, or OTf, in the presence ofan organic base such as, but not limited to, imidazole, TEA, DIPEA toproduce intermediate compound 12a, followed by deprotection of thecarboxylic acid with a suitable base in a protic solvent to producecompound (V). The preferred hydroxyl protecting agent is TBS-Cl. Thepreferred organic base is imidazole. The preferred base is K₂CO₃. Thepreferred protic solvent is MeOH. The reaction can be carried out at atemperature ranging from −10° C. to 50° C. In a preferred aspect, thereaction temperature is from 0° C. to 30° C. In another preferredaspect, the reaction temperature is about 25° C.

Compound (V) can be crystallized from organic solvent or mixture oforganic solvents such as, but not limited to hexanes/CH₂Cl₂ to providecompound (V) with purity greater than 95%.

In one embodiment, Step 3(b) is conducted as set forth in scheme 4. Themethod comprises the steps of 3(b)(i): reacting compound (V) with asuitable acylating reagent to produce compound 13; and 3(b)(ii):reducing compound 13 to produce compound (VI).

wherein R³ is as previously defined.

The process of the present application has never been reported in theart. The synthesis of compound (VI) has been described in US2016/0289262 from obeticholic acid in 6 steps. The synthesis ofobeticholic acid was reported in US 2013/0345188 starting from KLCA in 6steps. Overall, the known process of preparing alcohol compound (VI)involved a 12-step synthesis from KLCA. This previous process includedlow yielding steps, and required multiple column chromatography steps,which is expensive and not suitable for large scale commercialization.Additionally several toxic and dangerous reagents were used. The processof the present invention of preparing compound (V) takes six steps fromcompound (III) with good overall yield and requires only one columnchromatography operations. Key intermediates, such as compound 12, canbe obtained via crystallization in high purity. Also compound (V) can beobtained via crystallization in high purity. Compound (V) can beconverted to compound (VI) via mixed anhydride formation followed byreduction.

Step 3(b)(i), Converting Compound (V) to Compound 13:

Step 3(b)(i) is the reaction of compound (V) with a suitablechloroformate R³OCOCl in the presence of an organic base such as, butnot limited to, TEA or DIPEA to produce mixed anhydride 13. Step 3(b)(i)can be conducted in an aprotic solvent such as, but not limited to, DCM.The preferred chloroformate is isobutyl chloroformate, wherein R³ isisobutyl. The preferred organic base is TEA. Compound 13 is isolated incrude form and used without further purification.

Step 3(b)(ii), Converting Compound 13 to Compound (VI):

Step 3(b)(ii) is the reaction of compound 13 with a suitable reducingagent such as, but not limited to, NaBH₄, LiBH₄, LiAlH₄, or DIBAL toproduce compound (VI). Step 3(b)(ii) is preferably carried out in amixture of a protic and non-protic solvent, such as, but not limited toa mixture of water and THF. The reaction can be carried out at atemperature ranging from −10° C. to 50° C. In a preferred aspect, thereaction temperature is from 0° C. to 30° C. In another preferredaspect, the reaction temperature is about 25° C.

Compound VI can be purified by column chromatography to provide compoundVI with purity greater than 95%.

Process for Preparing a Compound of Formula (I)

The current invention also includes a process for preparing a compoundof Formula (I) starting with the compound (IV) as shown in Scheme 5.

wherein R⁴ is imidazol-1-yl, alkyl-O— aryl-O, Cl, or CCl₃; R¹ is aspreviously defined.Step 3(a)(i), Converting Compound (IV) to Compound of Formula 14:

Step 3(a)(i) involves converting the compound (IV) to a compound offormula 14, wherein R¹ is as previously defined, by reacting thecompound (IV) with a compound represented by 15E,

wherein, R⁴ is imidazol-1-yl, alkyl-O— aryl-O, Cl, or CCl₃, and R¹ is aspreviously defined, in the presence of an organic base. The reaction ispreferably carried in an aprotic solvent, such as, but not limited to,THF, DCM or toluene. In one preferred aspect, the reaction solvent isTHF. Suitable organic bases include, but are not limited to,triethylamine, and diisopropylethylamine. DMAP, ranging from 1 mol % to50 mol %, can be added to facilitate the reaction. The reactiontemperature preferably ranges from about 0° C. to about 80° C. In oneaspect, the reaction is carried out at about 0° C. In another aspect,the reaction is carried out at about room temperature (about 25° C.). Inyet another aspect, the reaction is carried out at about 50° C.

Preferably R⁴ in compound 15E is imidazol-1-yl, MeO—, EtO— or PhO—. Morepreferably R⁴ is PhO—.

Step 3(a)(ii) Converting Compound of Formula 14 to Compound of Formula(I):

Step 3(a)(ii) is the removal of the PG protecting group of compound 14to form compound (I), wherein R¹ is as previously defined. The PGprotecting group can be removed under suitable deprotection conditionsas are known in the art. The preferred PG protecting group is the TBS,Preferably, the protecting group is removed by a deprotecting reagentsuch as, but not limited to, TBAF, or an acid such as HCl. Preferablycompound 14 is treated with an acid in a protic solvent. Preferablycompound 14 is treated with an acid, such as HCl, in a protic solventsuch as, but not limited to, MeOH, EtOH, i-PrOH, H₂O, or a mixture oftwo. The preferred solvent is MeOH. The reaction can be carried out at atemperature ranging from −10° C. to 50° C. In a preferred aspect, thereaction temperature is from 0° C. to 30° C. In another preferredaspect, the reaction temperature is about 25° C.

Process to Prepare Compound (VII)

The process of the current invention also includes a process forpreparing compound (VII) starting from compound (IV) following theprocess described in Scheme 6.

The process involves the conversion of alcohol compound (IV) to asulfonyl carbamate 16 with an appropriate reagent, such as an agentselected from 15A, 15B, 15C and 15D, in the presence of an organic base.

In one aspect, the reagent is 15B which can be formed by reactingsulfonamide compound 15A with CDI.

In another aspect, the reagent is sulfonylcarbamate compound 15C,wherein R⁵ is alkyl or aryl, preferably methyl, ethyl, or phenyl. Thepreferred reagent is 15D.

In one aspect, the alcohol compound (IV) reacts with 15D in an aproticsolvent, such as, but not limited to, THF, DCM or toluene. In onepreferred aspect, the reaction solvent is THE. Suitable organic basesinclude, but are not limited to, triethylamine, diisopropylethylamine.DMAP, ranging from 1 mol % to 50 mol %, can be added to facilitate thereaction. The reaction temperature preferably ranges from about 0° C. toabout 80° C. In one aspect, the reaction is carried out at about 0° C.In another aspect, the reaction is carried out at about room temperature(about 25° C.). In yet another aspect, the reaction is carried out at a50° C. Compound 16 can be purified by column chromatography to providecompound 16 with purity greater than 95%.

In one aspect, compound 16 reacts with a deprotecting reagent such as,but not limited to, TBAF, or an acid such as HCl. Preferably compound 16is treated with an acid in a protic solvent. Preferably compound 16 istreated with an acid, such as HCl, in a protic solvent such as, but notlimited to, MeOH, EtOH, i-PrOH, H₂O, or a mixture of two. The preferredsolvent is MeOH. The reaction can be carried out at a temperatureranging from −10° C. to 50° C. In a preferred aspect, the reactiontemperature is from 0° C. to 30° C. In another preferred aspect, thereaction temperature is about 25° C. Compound (VII) can be purified bycolumn chromatography to provide compound (VII) with purity greater than95%.

Process to Prepare a Compound of Formula (II)

The current invention also includes a process for preparing a compoundof formula (II) starting with the compound (VI) as shown in Scheme 7.

Step 4(b)(i), Converting the Compound (VI) to Compound of Formula 17:

wherein R¹ and R⁴ are as previously defined. Preferably R⁴ in compound15E is imidazol-1-yl, MeO—, EtO— or PhO—. More preferably, R⁴ is PhO—.

The reaction is preferably carried in an aprotic solvent, such as, butnot limited to, THF, DCM or toluene. In one preferred aspect, thereaction solvent is THF. Suitable organic bases include, but are notlimited to, triethylamine, diisopropylethylamine, and DMAP. The reactiontemperature preferably ranges from about 0° C. to about 80° C. In oneaspect, the reaction is carried out at about 0° C. In another aspect,the reaction is carried out at about room temperature (about 25° C.). Inyet another aspect, the reaction is carried out at about 50° C.

Step 4(b)(ii), Converting Compound of Formula 17 to Compound of Formula(II):

Step 4(b)(ii) is the removal of the PG protecting group of compound offormula 17 to form compound (II), wherein PG, and R¹ is as previouslydefined. The PG protecting group can be removed under suitabledeprotection conditions as are known in the art. The preferred PGprotecting group is the TBS, Preferably, the protecting group is removedby a deprotecting reagent such as, but not limited to, TBAF, or an acidsuch as HCl. Preferably compound of formula 17 is treated with an acidin a protic solvent. Preferably compound of formula 17 is treated withan acid, such as HCl, in a protic solvent such as, but not limited to,MeOH, EtOH, i-PrOH, H₂O, or a mixture of two. The preferred solvent isMeOH. The reaction can be carried out at a temperature ranging from −10°C. to 50° C. In a preferred aspect, the reaction temperature is from 0°C. to 30° C. In another preferred aspect, the reaction temperature isabout 25° C.

Process to Prepare Compound (VIII)

The process of the current invention also includes a process ofpreparation of compound (VIII) starting from the compound (VI) followingthe process described in Scheme 8.

The process involves the conversion of alcohol compound (VI) to asulfonyl carbamate compound 18, followed by deprotection to producecompound (VIII). The conditions for the process described for Scheme 8are the same as were previously defined for Scheme 7.

The process involves the conversion of alcohol the compound (VI) to asulfonyl carbamate 18 with an appropriate reagent (for example, selectedfrom 15A-15D) in the presence of organic base.

In one aspect, the reagent is 15B which can be formed by reactingsulfonamide compound 15A with CDI.

In another aspect, the reagent can be sulfonylcarbamate compound 15C,wherein R⁵ is alkyl or aryl, preferably methyl, ethyl, or phenyl. Thepreferred reagent is 15D.

In one aspect, the alcohol compound (VI) reacts with 15D in an aproticsolvent, such as, but not limited to, THF, DCM or toluene. In onepreferred aspect, the reaction solvent is THF. Suitable organic basesinclude, but are not limited to, triethylamine anddiisopropylethylamine. DMAP, ranging from 1 mol % to 50 mol %, can beadded to facilitate the reaction. The reaction temperature preferablyranges from about 0° C. to about 80° C. In one aspect, the reaction iscarried out at about 0° C. In another aspect, the reaction is carriedout at about room temperature (about 25° C.). In yet another aspect, thereaction is carried out at a 50° C. Compound 18 can be purified bycolumn chromatography to provide compound 18 with purity greater than95%.

In one aspect, compound 18 reacts with a deprotecting reagent such as,but not limited to, TBAF, or an acid such as HCl. Preferably compound 18is treated with an acid in a protic solvent. Preferably compound 18 istreated with an acid, such as HCl, in a protic solvent such as, but notlimited to, MeOH, EtOH, i-PrOH, H₂O, or a mixture of two. The preferredsolvent is MeOH. The reaction can be carried out at a temperatureranging from −10° C. to 50° C. In a preferred aspect, the reactiontemperature is from 0° C. to 30° C. In another preferred aspect, thereaction temperature is about 25° C. Compound (VIII) can be purified bycolumn chromatography to provide compound (VIII) with purity greaterthan 95%.

Process to Prepare Compound (IX)

The process of the current invention also includes a process ofpreparation of compound (IX) starting from the compound (VI) followingthe process described in Scheme 9.

The process involves the conversion of alcohol the compound (VI) orcompound (VIb) to a sulfonyl carbamate compound (19) with an appropriatereagent, for example one of compounds 20A, 20B, 20C or 20D, in thepresence of organic base.

In one aspect, the reagent is 20B which can be formed by reactingsulfonamide compound 20A with CDI.

In another aspect, the reagent can be sulfonylcarbamate compound 20C,wherein R⁵ is alkyl or aryl, preferably methyl, ethyl, or phenyl. Thepreferred reagent is 20D.

In one aspect, the alcohol the compound (VI) reacts with 20D in anaprotic solvent, such as, but not limited to, THF, DCM or toluene. Inone preferred aspect, the reaction solvent is THF. Suitable organicbases include, but are not limited to, triethylamine,diisopropylethylamine, and DMAP. The reaction temperature preferablyranges from about 0° C. to about 80° C. In one aspect, the reaction iscarried out at about 0° C. In another aspect, the reaction is carriedout at about room temperature (about 25° C.). In yet another aspect, thereaction is carried out at a 50° C. Compound 19 can be purified bycolumn chromatography to provide compound 19 with purity greater than95%.

In one aspect, compound 19 reacts with a deprotecting reagent such as,but not limited to, TBAF, or an acid such as HCl. Preferably compound 19is treated with an acid in a protic solvent. Preferably compound 19 istreated with an acid, such as HCl, in a protic solvent such as, but notlimited to, MeOH, EtOH, i-PrOH, H₂O, or a mixture of two. The preferredsolvent is MeOH. The reaction can be carried out at a temperatureranging from −10° C. to 50° C. In a preferred aspect, the reactiontemperature is from 0° C. to 30° C. In another preferred aspect, thereaction temperature is about 25° C. Compound (IX) can be purified bycolumn chromatography to provide compound (IX) with purity greater than95%.

In another embodiment, the current invention also includes a process forpreparing a compound of formula (II) starting with the compound (VIb) asshown in Scheme 10, and preparing compound (VIb) is as shown in Scheme11.

Definitions

Listed below are definitions of various terms used to describe thisinvention. These definitions apply to the terms as they are usedthroughout this specification and claims, unless otherwise limited inspecific instances, either individually or as part of a larger group.

The term “alkyl”, as used herein, refers to a saturated, monovalentstraight- or branched-chain hydrocarbon group. Preferred alkyl radicalsinclude C₁-C₆ alkyl and C₁-C₈ alkyl radicals. Examples of C₁-C₆ alkylgroups include, but are not limited to, methyl, ethyl, propyl,isopropyl, n-butyl, tert-butyl, neopentyl, n-hexyl groups; and examplesof C₁-C₈ alkyl groups include, but are not limited to, methyl, ethyl,propyl, isopropyl, n-butyl, tert-butyl, neopentyl, n-hexyl, heptyl, andoctyl groups.

The term “alkenyl”, as used herein, denote a monovalent group derivedfrom a hydrocarbon moiety by the removal of a single hydrogen atomwherein the hydrocarbon moiety has at least one carbon-carbon doublebond. Preferred alkenyl groups include C₂-C₆ alkenyl and C₂-C₈ alkenylgroups. Alkenyl groups include, but are not limited to, for example,ethenyl, propenyl, butenyl, 1-methyl-2-buten-1-yl, heptenyl, octenyl andthe like.

The term “alkynyl”, as used herein, denotes a monovalent group derivedfrom a hydrocarbon moiety by the removal of a single hydrogen atomwherein the hydrocarbon moiety has at least one carbon-carbon triplebond. Preferred alkynyl groups include C₂-C₆ alkynyl and C₂-C₈ alkynylgroups. Representative alkynyl groups include, but are not limited to,for example, ethynyl, 1-propynyl, 1-butynyl, heptynyl, octynyl and thelike.

The term “cycloalkyl”, as used herein, refers to a monocyclic orpolycyclic saturated carbocyclic ring or a bi- or tri-cyclic groupfused, bridged or spiro system, and the carbon atoms may be optionallyoxo-substituted or optionally substituted with exocyclic olefinic doublebond. Preferred cycloalkyl groups include C₃-C₈ cycloalkyl and C₃-C₁₂cycloalkyl groups. Examples of C₃-C₈-cycloalkyl include, but are notlimited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,cyclopentyl and cyclooctyl; and examples of C₃-C₁₂-cycloalkyl include,but not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,cyclooctyl,bicyclo[2.2.1]heptyl, bicyclo[2.2.2]octyl,spiro[2.5]octyl,3-methylenebicyclo[3.2.1]octyl, spiro[4.4]nonanyl,bicycle[3.1.0]hexanyl, spiro[2.3]hexanyl, bicycle[3.1.1]heptanyl,spiro[2.5]octanyl, bicycle[4.1.0]heptanyl, bicycle[3.1.0]hexan-6-yl,spiro[2.3]hexan-5-yl, bicycle[3.1.1]heptan-3-yl, spiro[2.5]octan-4-yl,and bicycle[4.1.0]heptan-3-yl and the like.

The term “cycloalkenyl”, as used herein, refers to monocyclic orpolycyclic carbocyclic ring or a bi- or tri-cyclic group fused, bridgedor spiro system having at least one carbon-carbon double bond and thecarbon atoms may be optionally oxo-substituted or optionally substitutedwith exocyclic olefinic double bond. Preferred cycloalkenyl groupsinclude C₃-C₈ cycloalkenyl and C₃-C₁₂ cycloalkenyl groups. Examples ofC₃-C₈-cycloalkenyl include, but are not limited to, cyclopropenyl,cyclobutenyl, cyclopentenyl, cyclohexenyl, cycloheptenyl, cyclooctenyl,and the like; and examples of C₃-C₁₂-cycloalkenyl include, but notlimited to, cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl,cycloheptenyl, cyclooctenyl, bicyclo[2.2.1]hept-2-enyl,bicyclo[3.1.0]hex-2-enyl, spiro[2.5]oct-4-enyl, spiro[4.4]non-1-enyl,bicyclo[4.2.1]non-3-en-9-yl, and the like.

The terms “heterocyclic” or “heterocycloalkyl” can be usedinterchangeably and referred to a non-aromatic ring or a bi- ortri-cyclic group fused, bridged or spiro system, wherein (i) each ringsystem contains at least one heteroatom independently selected fromoxygen, sulfur and nitrogen, (ii) each ring system can be saturated orunsaturated (iii) the nitrogen and sulfur heteroatoms may optionally beoxidized, (iv) the nitrogen heteroatom may optionally be quaternized,(v) any of the above rings may be fused to an aromatic ring, and (vi)the remaining ring atoms are carbon atoms which may be optionallyoxo-substituted or optionally substituted with exocyclic olefinic doublebond. Representative heterocycloalkyl groups include, but are notlimited to, [1,3]dioxolane, pyrrolidinyl, pyrazolinyl, pyrazolidinyl,imidazolinyl, imidazolidinyl, piperidinyl, piperazinyl, oxazolidinyl,isoxazolidinyl, morpholinyl, thiazolidinyl, isothiazolidinyl,quinoxalinyl, pyridazinonyl, tetrahydrofuryl,2-azabicyclo[2.2.1]-heptyl, 8-azabicyclo[3.2.1]octyl,5-azaspiro[2.5]octyl, 1-oxa-7-azaspiro[4.4]nonanyl, 7-oxooxepan-4-yl,and tetrahydrofuryl. Such heterocyclic groups may be furthersubstituted. Heteroaryl or heterocyclic groups can be C-attached orN-attached (where possible).

The term “aryl,” as used herein, refers to a mono- or polycycliccarbocyclic ring system comprising at least one aromatic ring,including, but not limited to, phenyl, naphthyl, tetrahydronaphthyl,indanyl, and indenyl. A polycyclic aryl is a polycyclic ring system thatcomprises at least one aromatic ring. Polycyclic aryls can comprisefused rings, covalently attached rings or a combination thereof.

The term “arylalkyl,” as used herein, refers to a functional groupwherein an alkylene chain is attached to an aryl group, e.g.,—CH₂CH₂-phenyl. The term “substituted arylalkyl” means an arylalkylfunctional group in which the aryl group is substituted. Examplesinclude, but are not limited to, benzyl, phenethyl and the like.Preferred arylalkyl groups include aryl-C₁-C₈-alkyl groups.

The term “heteroaryl,” as used herein, refers to a mono-, bi-, ortri-cyclic group comprising at least one 5- or 6-membered aromatic ringcomprising at least one ring atom selected from S, O and N. Preferredheteroaryl groups are monocyclic or bicyclic. Heteroaryl groups includemonocyclic groups having 5 or 6 ring atoms and fused bicyclic groupscomprising 8 to 10 ring atoms. Heteroaryl groups include, but are notlimited to, pyridinyl, pyrazolyl, pyrazinyl, pyrimidinyl, pyrrolyl,pyrazolyl, imidazolyl, thiazolyl, thienyl, triazolyl, isothiazolyl,oxazolyl, isoxazolyl, thiadiazolyl, oxadiazolyl, thiophenyl, furanyl,quinolinyl, isoquinolinyl, benzimidazolyl, benzooxazolyl, benzothienyl,quinoxalyl, indolyl, indazolyl, benzisoxazolyl, benzofuranyl,benzotriazolyl, benzothiazolyl, and the like.

The term “heteroarylalkyl,” as used herein, refers to an alkylene chainis attached to a heteroaryl group. The term “substitutedheteroarylalkyl” means a heteroarylalkyl functional group in which theheteroaryl group is substituted. Examples include, but are not limitedto, pyridinylmethyl, pyrimidinylethyl and the like. Preferredheteroarylalkyl groups include heteroaryl-C₁-C₈-alkyl groups.

The term “biaryl”, as used herein, refers to a moiety consisting of twoaryl groups, two heteroaryl groups or an aryl group and a heteroarylgroup, wherein the two groups are connected by a single bond. Asubstituted biaryl group is a biaryl moiety in which at least one of theconnected groups has at least one non-hydrogen substituent. Examples ofbiaryl groups include biphenyl, pyridylphenyl, pyrimidylphenyl,pyrimidypyridyl, and pyrimidyloxadizolyl groups.

The term “aryl-heterocyclyl” refers to a bicyclic group comprising amonocyclic aryl or heteroaryl group connected to a heterocyclic group bya single bond. Examples of aryl-heterocyclyl groups includephenyl-piperidinyl and pyridyl-piperidinyl groups.

As used herein, the term “alkoxy” employed alone or in combination withother terms means, unless otherwise stated, an alkyl group having thedesignated number of carbon atoms connected to the rest of the moleculevia an oxygen atom, such as, for example, methoxy, ethoxy, 1-propoxy,2-propoxy (isopropoxy) and the higher homologs and isomers. Preferredalkoxy are (C₁-C₃) alkoxy.

The term “substituted” refers to substitution by independent replacementof one, two, or three or more of the hydrogen atoms with substituentsincluding, but not limited to, —F, —Cl, —Br, —I, —OH, C₁-C₁₂-alkyl;C₂-C₁₂-alkenyl, C₂-C₁₂-alkynyl, protected hydroxy, —NO₂, —N₃, —CN, —NH₂,protected amino, oxo, thioxo, —NH—C₁-C₁₂-alkyl, —NH—C₂-C₅-alkenyl,—NH—C₂-C₈-alkynyl, —NH—C₃-C₂-cycloalkyl, —NH-aryl, —NH-heteroaryl,—NH-heterocycloalkyl, -dialkylamino, -diarylamino, -diheteroarylamino,—O—C₁-C₁₂-alkyl, —O—C₂-C₈-alkenyl, —O—C₂-C₈-alkynyl,—O—C₃-C₁₂-cycloalkyl, —O-aryl, —O-heteroaryl, —O-heterocycloalkyl,—C(O)—C₁-C₁₂-alkyl, —C(O)—C₂-C₈-alkenyl, —C(O)—C₂-C₈-alkynyl,—C(O)—C₃-C₁₂-cycloalkyl, —C(O)-aryl, —C(O)-heteroaryl, —C(O)—heterocycloalkyl, —CONH₂, —CONH—C₁-C₁₂-alkyl, —CONH—C₂-C₈-alkenyl,—CONH—C₂-C₈-alkynyl, —CONH—C₃-C₁₂-cycloalkyl, —CONH-aryl,—CONH-heteroaryl, —CONH-heterocycloalkyl, —OCO₂—C₁-C₁₂-alkyl,—OCO₂—C₂-C₈-alkenyl, —OCO₂—C₂-C₈-alkynyl, —OCO₂—C₃-C₂-cycloalkyl,—OCO₂-aryl, —OCO₂-heteroaryl, —OCO₂-heterocycloalkyl, —CO₂—C₁-C₁₂ alkyl,—CO₂—C₂-C₈ alkenyl, —CO₂—C₂-C₈ alkynyl, CO₂—C₃-C₁₂-cycloalkyl, —CO₂—aryl, CO₂-heteroaryl, CO₂-heterocyloalkyl, —OCONH₂, —OCONH—C₁-C₁₂-alkyl,—OCONH—C₂-C₈-alkenyl, —OCONH—C₂-C₈-alkynyl, —OCONH—C₃-C₂-cycloalkyl,—OCONH-aryl, —OCONH-heteroaryl, —OCONH-heterocyclo-alkyl, —NHC(O)H,—NHC(O)—C₁-C₁₂-alkyl, —NHC(O)—C₂-C₈-alkenyl, —NHC(O)—C₂-C₈-alkynyl,—NHC(O)—C₃-C₂-cycloalkyl, —NHC(O)-aryl, —NHC(O)-heteroaryl,—NHC(O)-heterocyclo-alkyl, —NHCO₂—C₁-C₁₂-alkyl, —NHCO₂—C₂-C₈-alkenyl,—NHCO₂—C₂-C₈-alkynyl, —NHCO₂—C₃-C₁₂-cycloalkyl, —NHCO₂-aryl,—NHCO₂-heteroaryl, —NHCO₂— heterocycloalkyl, —NHC(O)NH₂,—NHC(O)NH—C₁-C₁₂-alkyl, —NHC(O)NH—C₂-C₈-alkenyl,—NHC(O)NH—C₂-C₈-alkynyl, —NHC(O)NH—C₃-C₁₂-cycloalkyl, —NHC(O)NH-aryl,—NHC(O)NH-heteroaryl, —NHC(O)NH— heterocycloalkyl, NHC(S)NH₂,—NHC(S)NH—C₁-C₁₂-alkyl, —NHC(S)NH—C₂-C₈-alkenyl,—NHC(S)NH—C₂-C₈-alkynyl, —NHC(S)NH—C₃-C₁₂-cycloalkyl, —NHC(S)NH-aryl,—NHC(S)NH— heteroaryl, —NHC(S)NH-heterocycloalkyl, —NHC(NH)NH₂,—NHC(NH)NH—C₁-C₁₂-alkyl, —NHC(NH)NH—C₂-C₈-alkenyl,—NHC(NH)NH—C₂-C₈-alkynyl, —NHC(NH)NH—C₃-C₁₂-cycloalkyl, —NHC(NH)NH-aryl,—NHC(NH)NH-heteroaryl, —NHC(NH)NH-heterocycloalkyl,—NHC(NH)—C₁-C₁₂-alkyl, —NHC(NH)—C₂-C₈-alkenyl, —NHC(NH)—C₂-C₈-alkynyl,—NHC(NH)—C₃-C₁₂-cycloalkyl, —NHC(NH)-aryl, —NHC(NH)-heteroaryl,—NHC(NH)-heterocycloalkyl, —C(NH)NH—C₁-C₁₂-alkyl,—C(NH)NH—C₂-C₈-alkenyl, —C(NH)NH—C₂-C₈-alkynyl,—C(NH)NH—C₃-C₁₂-cycloalkyl, —C(NH)NH-aryl, —C(NH)NH-heteroaryl,—C(NH)NH-heterocycloalkyl, —S(O)—C₁-C₁₂-alkyl, —S(O)—C₂-C₈-alkenyl,—S(O)—C₂-C₈-alkynyl, —S(O)—C₃-C₁₂-cycloalkyl, —S(O)-aryl,—S(O)-heteroaryl, —S(O)-heterocycloalkyl, —SO₂NH₂, —SO₂NH—C₁-C₁₂-alkyl,—SO₂NH—C₂-C₈-alkenyl, —SO₂NH—C₂-C₈-alkynyl, —SO₂NH—C₃-C₁₂-cycloalkyl,—SO₂NH-aryl, —SO₂NH-heteroaryl, —SO₂NH-heterocycloalkyl,—NHSO₂—C₁-C₁₂-alkyl, —NHSO₂—C₂-C₈-alkenyl, —NHSO₂—C₂-C₈-alkynyl,—NHSO₂—C₃-C₁₂-cycloalkyl, —NHSO₂-aryl, —NHSO₂-heteroaryl,—NHSO₂-heterocycloalkyl, —CH₂NH₂, —CH₂SO₂CH₃, -aryl, -arylalkyl,-heteroaryl, -heteroarylalkyl, -heterocycloalkyl, —C₃-C₁₂-cycloalkyl,polyalkoxyalkyl, polyalkoxy, -methoxymethoxy, -methoxyethoxy, —SH,—S—C₁-C₁₂-alkyl, —S—C₂-C₈-alkenyl, —S—C₂-C₈-alkynyl,—S—C₃-C₁₂-cycloalkyl, —S-aryl, —S-heteroaryl, —S— heterocycloalkyl, ormethylthio-methyl. It is understood that the aryls, heteroaryls, alkyls,cycloalkyls and the like can be further substituted. In some cases, eachsubstituent in a substituted moiety is additionally optionallysubstituted with one or more groups, each group being independentlyselected from —F, —Cl, —Br, —I, —OH, —NO₂, —CN, or —NH₂.

The term “optionally substituted”, as used herein, means that thereferenced group may be substituted or unsubstituted. In one embodiment,the referenced group is optionally substituted with zero substituents,i.e., the referenced group is unsubstituted. In another embodiment, thereferenced group is optionally substituted with one or more additionalgroup(s) individually and independently selected from groups describedherein.

In accordance with the invention, any of the aryls, substituted aryls,heteroaryls and substituted heteroaryls described herein, can be anyaromatic group. Aromatic groups can be substituted or unsubstituted.

It is understood that any alkyl, alkenyl, alkynyl, cycloalkyl andcycloalkenyl moiety described herein can also be an aliphatic group, analicyclic group or a heterocyclic group. An “aliphatic group” isnon-aromatic moiety that may contain any combination of carbon atoms,hydrogen atoms, halogen atoms, oxygen, nitrogen or other atoms, andoptionally contain one or more units of unsaturation, e.g., doubleand/or triple bonds. An aliphatic group may be straight chained,branched or cyclic and preferably contains between about 1 and about 24carbon atoms, more typically between about 1 and about 12 carbon atoms.In addition to aliphatic hydrocarbon groups, aliphatic groups include,for example, polyalkoxyalkyls, such as polyalkylene glycols, polyamines,and polyimines, for example. Such aliphatic groups may be furthersubstituted. It is understood that aliphatic groups may be used in placeof the alkyl, alkenyl, alkynyl, alkylene, alkenylene, and alkynylenegroups described herein.

The term “alicyclic,” as used herein, denotes a monovalent group derivedfrom a monocyclic or polycyclic saturated carbocyclic ring compound bythe removal of a single hydrogen atom. Examples include, but are notlimited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl,bicyclo[2.2.1]heptyl, and bicyclo[2.2.2]octyl. Such alicyclic groups maybe further substituted.

It will be apparent that in various embodiments of the invention, thesubstituted or unsubstituted alkyl, alkenyl, alkynyl, cycloalkyl,cycloalkenyl, cycloalkynyl, arylalkyl, heteroarylalkyl, andheterocycloalkyl are intended to be monovalent or divalent. Thus,alkylene, alkenylene, and alkynylene, cycloaklylene, cycloalkenylene,cycloalkynylene, arylalkylene, heteroarylalkylene andheterocycloalkylene groups are to be included in the above definitions,and are applicable to provide the Formulas herein with proper valency.

The term “hydroxyl protecting agent”, as used herein, is a compoundrepresented by PG-X, PG¹-X or PG-X, where PG, PG¹ and PG³ are as definedherein and X is a suitable leaving group, preferably a halogen, an alkylsulfonate or a fluoroalkylsulfonate. Preferably, X is Cl, Br, I, ortriflate (OTf). A hydroxyl protecting agent wherein PG, PG¹ or PG³ is asilyl group is alternatively referred to herein as a “silylating agent”.

The terms “halo” and “halogen,” as used herein, refer to an atomselected from fluorine, chlorine, bromine and iodine.

The term “hydrogen” includes hydrogen and deuterium. In addition, therecitation of an atom includes other isotopes of that atom so long asthe resulting compound is pharmaceutically acceptable.

The term “hydroxyl protecting group,” as used herein, refers to a labilechemical moiety which is known in the art to protect a hydroxyl groupagainst undesired reactions during synthetic procedures. After saidsynthetic procedure(s) the hydroxyl protecting group as described hereinmay be selectively removed. Hydroxyl protecting groups as known in theart are described generally in T. H. Greene and P. G. M. Wuts,Protective Groups in Organic Synthesis, 3rd edition, John Wiley & Sons,New York (1999). Examples of hydroxyl protecting groups includebenzyloxycarbonyl, 4-methoxybenzyloxycarbonyl, tert-butoxy-carbonyl,isopropoxycarbonyl, diphenylmethoxycarbonyl,2,2,2-trichloroethoxycarbonyl, allyloxycarbonyl, acetyl, formyl,chloroacetyl, trifluoroacetyl, methoxyacetyl, phenoxyacetyl, benzoyl,methyl, t-butyl, 2,2,2-trichloroethyl, 2-trimethylsilyl ethyl, allyl,benzyl, triphenyl-methyl (trityl), methoxymethyl, methylthiomethyl,benzyloxymethyl, 2-(trimethylsilyl)-ethoxymethyl, methanesulfonyl,trimethylsilyl, triisopropylsilyl, and the like.

The term “protected hydroxyl,” as used herein, refers to a hydroxylgroup protected with a hydroxyl protecting group, as defined above,including benzoyl, acetyl, trimethylsilyl, triethylsilyl, methoxymethylgroups, for example.

When the compounds described herein contain one or more asymmetriccenters they give rise to enantiomers, diastereomers, and otherstereoisomeric forms that may be defined, in terms of absolutestereochemistry, as (R)- or (S)-, or as (D)- or (L)-for amino acids. Thepresent invention is meant to include all such possible isomers, as wellas their racemic and optically pure forms. Optical isomers may beprepared from their respective optically active precursors by theprocedures described above, or by resolving the racemic mixtures. Theresolution can be carried out in the presence of a resolving agent, bychromatography or by repeated crystallization or by some combination ofthese techniques, which are known to those skilled in the art. Furtherdetails regarding resolutions can be found in Jacques, et al.,Enantiomers, Racemates, and Resolutions (John Wiley & Sons, 1981). Whenthe compounds described herein contain olefinic double bonds or othercenters of geometric asymmetry, and unless specified otherwise, it isintended that the compounds include both E and Z geometric isomers.Likewise, all tautomeric forms are also intended to be included. Theconfiguration of any carbon-carbon double bond appearing herein isselected for convenience only and is not intended to designate aparticular configuration unless the text so states; thus, acarbon-carbon double bond depicted arbitrarily herein as trans may becis, trans, or a mixture of the two in any proportion.

As used herein, the term “pharmaceutically acceptable salt” refers tothose salts of the compounds formed by the process of the presentinvention which are, within the scope of sound medical judgment,suitable for use in contact with the tissues of humans and lower animalswithout undue toxicity, irritation, allergic response and the like, andare commensurate with a reasonable benefit/risk ratio. Pharmaceuticallyacceptable salts are well known in the art.

Berge, et al. describes pharmaceutically acceptable salts in detail inJ. Pharmaceutical Sciences, 66: 1-19 (1977). The salts can be preparedin situ during the final isolation and purification of the compounds ofthe invention, or separately by reaction of the free base function witha suitable organic acid. Examples of pharmaceutically acceptable saltsinclude, but are not limited to, nontoxic acid addition salts e.g.,salts of an amino group formed with inorganic acids such as hydrochloricacid, hydrobromic acid, phosphoric acid, sulfuric acid and perchloricacid or with organic acids such as acetic acid, maleic acid, tartaricacid, citric acid, succinic acid or malonic acid or by using othermethods used in the art such as ion exchange. Other pharmaceuticallyacceptable salts include, but are not limited to, adipate, alginate,ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate,butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate,digluconate, dodecylsulfate, ethanesulfonate, formate, fumarate,glucoheptonate, glycerophosphate, gluconate, hemisulfate, heptanoate,hexanoate, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate,lactate, laurate, lauryl sulfate, malate, maleate, malonate,methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate,oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate,phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate,tartrate, thiocyanate, p-toluenesulfonate, undecanoate, valerate salts,and the like. Representative alkali or alkaline earth metal saltsinclude sodium, lithium, potassium, calcium, magnesium, and the like.Further pharmaceutically acceptable salts include, when appropriate,nontoxic ammonium, quaternary ammonium, and amine cations formed usingcounterions such as halide, hydroxide, carboxylate, sulfate, phosphate,nitrate, alkyl having from 1 to 6 carbon atoms, sulfonate and arylsulfonate.

The term “treating”, as used herein, means relieving, lessening,reducing, eliminating, modulating, or ameliorating, i.e., causingregression of the disease state or condition. Treating can also includeinhibiting, i.e., arresting the development, of an existing diseasestate or condition, and relieving or ameliorating, i.e., causingregression of an existing disease state or condition, for example whenthe disease state or condition may already be present.

The term “preventing”, as used herein means, to completely or almostcompletely stop a disease state or condition, from occurring in apatient or subject, especially when the patient or subject ispredisposed to such or at risk of contracting a disease state orcondition.

Additionally, the compounds of the present invention, for example, thesalts of the compounds, can exist in either hydrated or unhydrated (theanhydrous) form or as solvates with other solvent molecules. Nonlimitingexamples of hydrates include monohydrates, dihydrates, etc. Nonlimitingexamples of solvates include ethanol solvates, acetone solvates, etc.

The term “Lewis acid” refers to a substance that accepts an electronpair from a base, forming a covalent bond with the base. Also defined inliterature such as “Advanced Organic Chemistry” Jerry March, 4thedition, published by Wiely Interscience.

“Solvates” means solvent addition forms that contain eitherstoichiometric or non-stoichiometric amounts of solvent. Some compoundshave a tendency to trap a fixed molar ratio of solvent molecules in thecrystalline solid state, thus forming a solvate. If the solvent is waterthe solvate formed is a hydrate, when the solvent is alcohol, thesolvate formed is an alcoholate. Hydrates are formed by the combinationof one or more molecules of water with one of the substances in whichthe water retains its molecular state as H₂O, such combination beingable to form one or more hydrate.

As used herein, the term “analog” refers to a chemical compound that isstructurally similar to another but differs slightly in composition (asin the replacement of one atom by an atom of a different element or inthe presence of a particular functional group, or the replacement of onefunctional group by another functional group). Thus, an analog is acompound that is similar to or comparable in function and appearance tothe reference compound.

The term “aprotic solvent,” as used herein, refers to a solvent that isrelatively inert to proton activity, i.e., not acting as a proton-donor.Examples include, but are not limited to, hydrocarbons, such as hexaneand toluene, for example, halogenated hydrocarbons, such as, forexample, methylene chloride, ethylene chloride, chloroform, and thelike, heterocyclic compounds, such as, for example, tetrahydrofuran andN-methylpyrrolidinone, and ethers such as diethyl ether,bis-methoxymethyl ether. Such solvents are well known to those skilledin the art, and individual solvents or mixtures thereof may be preferredfor specific compounds and reaction conditions, depending upon suchfactors as the solubility of reagents, reactivity of reagents andpreferred temperature ranges, for example. Further discussions ofaprotic solvents may be found in organic chemistry textbooks or inspecialized monographs, for example: Organic Solvents PhysicalProperties and Methods of Purification, 4th ed., edited by John A.Riddick et al., Vol. II, in the Techniques of Chemistry Series, JohnWiley & Sons, N Y, 1986.

The terms “protogenic organic solvent” or “protic solvent” as usedherein, refer to a solvent that tends to provide protons, such as analcohol, for example, methanol, ethanol, propanol, isopropanol, butanol,t-butanol, and the like. Such solvents are well known to those skilledin the art, and individual solvents or mixtures thereof may be preferredfor specific compounds and reaction conditions, depending upon suchfactors as the solubility of reagents, reactivity of reagents andpreferred temperature ranges, for example. Further discussions ofprotogenic solvents may be found in organic chemistry textbooks or inspecialized monographs, for example: Organic Solvents PhysicalProperties and Methods of Purification, 4th ed., edited by John A.Riddick et al., Vol. II, in the Techniques of Chemistry Series, JohnWiley & Sons, N Y, 1986.

Combinations of substituents and variables envisioned by this inventionare only those that result in the formation of stable compounds. Theterm “stable”, as used herein, refers to compounds which possessstability sufficient to allow manufacture and which maintains theintegrity of the compound for a sufficient period of time to be usefulfor the purposes detailed herein (e.g., therapeutic or prophylacticadministration to a subject).

The synthesized compounds can be separated from a reaction mixture andfurther purified by a method such as column chromatography, highpressure liquid chromatography, or recrystallization. Additionally, thevarious synthetic steps may be performed in an alternate sequence ororder to give the desired compounds. In addition, the solvents,temperatures, reaction durations, etc. delineated herein are forpurposes of illustration only and variation of the reaction conditionscan produce the desired isoxazole products of the present invention.Synthetic chemistry transformations and protecting group methodologies(protection and deprotection) useful in synthesizing the compoundsdescribed herein include, for example, those described in R. Larock,Comprehensive Organic Transformations, VCH Publishers (1989); T. W.Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis, 2d.Ed., John Wiley and Sons (1991); L. Fieser and M. Fieser, Fieser andFieser's Reagents for Organic Synthesis, John Wiley and Sons (1994); andL. Paquette, ed., Encyclopedia of Reagents for Organic Synthesis, JohnWiley and Sons (1995).

The compounds of this invention may be modified by appending variousfunctionalities via synthetic means delineated herein to enhanceselective biological properties. Such modifications include those whichincrease biological penetration into a given biological system (e.g.,blood, lymphatic system, central nervous system), increase oralavailability, increase solubility to allow administration by injection,alter metabolism and alter rate of excretion.

Abbreviations

Abbreviations which have been used in the descriptions of the schemesand the examples that follow are:

-   -   Ac for acetyl;    -   AcOH for acetic acid;    -   ACN for acetonitrile;    -   aq. for aqueous;    -   BA for bile acid;    -   Brine for sodium chloride solution in water;    -   n-BuLi for n-butyl lithium;    -   cAMP for cyclic adenosine monophosphate;    -   CDCA for chenodeoxycholic acid;    -   CDI for carbonyldiimidazole;    -   CTX for cerebrotendinous xanthomatosis;    -   D2 for type 2 iodothyronine deiodinase;    -   DABCO for 1,4-diazabicyclo[2.2.2]octane;    -   DBN for 1,5-Diazabicyclo[4.3.0]non-5-ene;    -   DBU for 1,8-diazabicyclo[5.4.0]undec-7-ene;    -   DCM for dichloromethane;    -   DIBAL for diisobutylaluminium hydride;    -   DIPEA or (i-Pr)₂EtN for N,N-diisopropylethyl amine;    -   Dess-Martin periodinane for        1,1,1-tris(acetyloxy)-1,1-dihydro-1,2-benziodoxol-3-(1H)-one;    -   DMAP for 4-dimethylamino-pyridine;    -   DMF for N,N-dimethylformamide;    -   DMSO for dimethyl sulfoxide;    -   DPPA for diphenyl phosphoryl azide;    -   EtOAc for ethyl acetate;    -   EtOH for ethanol;    -   Et₂O for diethyl ether;    -   eq. for equivalent;    -   FXR for farnesoid x receptor;    -   GLP-1 for glucagon-like peptide 1    -   hrs for hours;    -   IBX for 2-iodoxybenzoic acid;    -   KHMDS for potassium bis(trimethylsilyl)amide;    -   KLCA for 7-ketolithocholic acid;    -   OTf or triflate for trifluoromethanesulfonate;    -   Ph for phenyl;    -   LDA for lithium diisopropylamide;    -   LiHMDS for lithium bis(trimethylsilyl)amide;    -   min for minutes;    -   MOM for methoxymethyl;    -   MEM for methoxyethoxymethyl;    -   NAFLD for nonalcoholic fatty liver disease;    -   NaHMDS for sodium bis(trimethylsilyl)amide;    -   NASH for nonalcoholic steatohepatitis;    -   NBS for N-bromosuccinimide;    -   NIS for N-iodosuccinimide;    -   NMO for N-methylmorpholine N-oxide;    -   o/n for overnight;    -   PBC for primary biliary cirrhosis;    -   PCC for pyridinium chlorochromate;    -   PDC for pyridinium dichromate;    -   Pd/C for palladium on carbon;    -   PNAC for parenteral nutrition associated cholestasis;    -   PSC for primary sclerosing cholangitis;    -   i-PrOAc for isopropyl acetate;    -   psi for pounds per square inch;    -   rt for room temperature;    -   sat. for saturated;    -   SEM for 2-trimethylsilylethoxymethyl;    -   TBAF for tetrabutylammonium fluoride;    -   TBDPS: for tert-butyl diphenylsilyl;    -   TBS for tert-butyl dimethylsilyl;    -   TEA or Et₃N for triethylamine;    -   TES for triethylsilyl;    -   TFA or CF₃COOH for trifluoroacetic acid;    -   THE for tetrahydrofuran;    -   THP for tetrahydropyranyl;    -   TIPS for triisopropylsilyl;    -   TMS for trimethylsilyl;    -   TMSCl for trimethylsilyl chloride;    -   TMSOTf for trimethylsilyl trifluoromethanesulfonate;    -   TBME or MTBE for tert-butyl methyl ether;    -   TLC for thin layer chromatography.

All other abbreviations used herein, which are not specificallydelineated above, shall be accorded the meaning which one of ordinaryskill in the art would attach.

All references cited herein, whether in print, electronic, computerreadable storage media or other form, are expressly incorporated byreference in their entirety, including but not limited to, abstracts,articles, journals, publications, texts, treatises, internet web sites,databases, patents, and patent publications.

Examples

The compounds and processes of the present invention will be betterunderstood in connection with the following examples, which are intendedas an illustration only and not limiting of the scope of the invention.Various changes and modifications to the disclosed embodiments will beapparent to those skilled in the art and such changes and modificationsincluding, without limitation, those relating to the chemicalstructures, substituents, derivatives, formulations and/or methods ofthe invention may be made without departing from the spirit of theinvention and the scope of the appended claims.

Example 1. Preparation of Compound 2 from Compound 1

To a solution of compound 1 (101.2 g, 258 mmol, 1.0 eq) in MeOH (607 mL,6v) in a 2 L flask was charged acetyl chloride (2.0 g, 1.8 mL, 25.8mmol, 0.1 eq) and the reaction was stirred for 18 h. The reaction wasconcentrated under reduced pressure and co-distilled with THF (2×300mL). The resultant residue was dried under vacuum to give 105 g of crudecompound 2 (HPLC purity: 99.6%) as a colorless amorphous solidcontaining THF. This material was used in the next step without furtherpurification. ¹H NMR (400 MHz, Chloroform-d) δ 3.84 (q, J=3.1 Hz, 1H),3.65 (s, 3H), 3.45 (tt, J=11.1, 4.4 Hz, 1H), 2.34 (ddd, J=15.3, 10.1,5.2 Hz, 1H), 2.28-2.13 (comp, 2H), 2.03-1.92 (comp, 3H), 1.87-1.76(comp, 4H), 1.74-1.58 (comp, 5H), 1.55-1.04 (comp, 10H), 0.99 (dd,J=14.2, 3.4 Hz, 1H), 0.91 (d, J=6.4 Hz, 3H), 0.89 (s, 3H), 0.65 (s, 3H).

Example 2. Preparation of Compound 3 from Compound 2

To a solution of diisopropylamine (53.5 g, 75.0 mL, 529 mmol, 4.1 eq) inanhydrous THF (143 mL, 2.7v) at −78° C. was charged n-BuLi (206 mL of a2.5M solution in hexanes, 516 mmol, 4.0 eq) dropwise. The reaction wasstirred for 15 min at −78° C., whereupon TMSCl (84.0 g, 99.0 mL, 774mmol, 6.0 eq) was added. A solution of compound 2 (52.5 g, 129 mmol, 1.0eq) in anhydrous THF (322 mL, 6.2v) was added dropwise at −78° C. Thereaction was warmed to room temperature and stirred for 3 hrs. Thereaction was cooled to −78° C. and a solution of I₂ (45.8 g, 181 mmol,1.4 eq) in anhydrous THF (401 mL, 7.6v) was added dropwise. The reactionwas stirred for 0.5 hrs at −78° C. The reaction was poured into anaqueous 10% NH₄Cl solution (600 mL) and diluted with MTBE (600 mL). Thelayers were separated and the aqueous layer was extracted with MTBE(2×300 mL). The combined organic layers were washed with an aqueous 10%Na₂S₂O₃ solution (2×400 mL), brine (400 mL), dried (MgSO₄), filtered,and concentrated to give 118 g crude compound 3 as a yellow gum. Thismaterial was used in the next step without further purification.Compound 3 was isolated as a ˜1:1 mixture of diastereomers: ¹H NMR (400MHz, Chloroform-d) δ 4.48 (dd, J=12.3, 3.8 Hz, 0.5H), 4.37 (dd, J=11.2,4.0 Hz, 0.5H), 3.79-3.72 (comp, 6H), 3.41 (tt, J=10.2, 4.5 Hz, 1H),2.60-2.47 (m, 0.5H), 2.32 (q, J=13.1 Hz, 1H), 2.18 (ddd, J=14.4, 11.1,2.7 Hz, 0.5H), 1.99-1.71 (comp, 6H), 1.70-0.95 (comp, 14H), 0.92 (d,J=6.4 Hz, 1.5H), 0.89 (d, J=6.5 Hz, 1.5H), 0.86 (d, J=5.1 Hz, 3H), 0.67(s, 1.5H), 0.59 (s, 1.5H), 0.16 (s, 9H), 0.10 (s, 9H).

Example 3. Preparation of Compound 4 from Compound 3

To a solution of crude compound 3 (87 g, 129 mmol, 1.0 eq) in anhydrousTHE (1071 mL, 12.3v) was charged DBU (58.7 g, 58.1 mL, 386 mmol, 3.0 eq)and the reaction was stirred for 48 hrs. The reaction was quenched withaqueous 10% NH₄Cl (600 mL) and diluted with MTBE (600 mL). The layerswere separated and the aqueous layer was extracted with MTBE (2×300 mL).The combined organic layers were dried (MgSO₄), filtered, andconcentrated to give 80 g crude compound 4 as a brown gum. This materialwas used in the next step without further purification. ¹H NMR (400 MHz,Chloroform-d) δ 6.84 (dd, J=15.6, 9.0 Hz, 1H), 5.72 (d, J=15.6 Hz, 1H),3.76 (qd, J=6.8, 6.0, 3.3 Hz, 1H), 3.71 (s, 3H), 3.40 (tt, J=10.8, 4.6Hz, 1H), 2.39-2.18 (comp, 2H), 2.00-1.11 (m, 18H), 1.07 (d, J=6.6 Hz,3H), 1.04-0.90 (comp, 2H), 0.86 (s, 3H), 0.65 (s, 3H), 0.10 (s, 9H),0.07 (s, 9H).

Example 4. Preparation of Compound 5 from Compound 4

To a solution of crude compound 4 (70.6 g, 129 mmol, 1.0 eq) inanhydrous THE (334 mL, 4.7v) was charged 4M HCl in 1,4-dioxane (33.4 mL,0.47v) and the reaction was stirred for 16 hrs. The reaction wasconcentrated under reduced pressure and co-distilled with DCM (1×400mL). The resultant brown gum was purified by column chromatographyeluting with hexanes/acetone (5% acetone→35% acetone, 2×330 g column) togive compound 5 (32.2 g, 80.0 mmol, 62% yield over 4 steps. ¹H NMR (400MHz, Chloroform-d) δ 6.83 (dd, J=15.6, 9.0 Hz, 1H), 5.73 (dd, J=15.6,0.9 Hz, 1H), 3.84 (q, J=3.1 Hz, 1H), 3.71 (s, 3H), 3.51-3.40 (m, 1H),2.33-2.13 (comp, 2H), 2.03-1.91 (comp, 2H), 1.91-1.78 (comp, 2H),1.78-1.57 (comp, 4H), 1.55-1.11 (comp, 11H), 1.08 (d, J=6.6 Hz, 3H),0.98 (td, J=14.1, 3.3 Hz, 1H), 0.90 (s, 3H), 0.69 (s, 3H).

Example 5. Preparation of Compound 6 from Compound 5

To a solution of compound 5 (32.2 g, 80.0 mmol, 1.0 eq) and imidazole(10.8 g, 159 mmol, 2.0 eq) in anhydrous THF (166 mL, 5.2v) and DMF (33.2mL, 1v) at 0° C. was charged TBSCl (13.2 g, 88.0 mmol, 1.2 eq). Thereaction was warmed to room temperature and stirred for 3 hrs. Uponcompletion, the reaction was concentrated to remove most of the THF.Diluted with MTBE (300 mL) and H₂O (300 mL). The layers were separatedand the organic layer was washed with aqueous 10% citric acid (150 mL),H₂O (150 mL), saturated aqueous NaHCO₃ (150 mL), H₂O (150 mL), and brine(150 mL). The organic layer was dried (MgSO₄), filtered, andconcentrated to give crude compound 6 (44 g). as a colorless amorphoussolid. This material was used in the next step without furtherpurification. ¹H NMR (500 MHz, Chloroform-d) δ 6.83 (dd, J=15.6, 9.0 Hz,1H), 5.73 (d, J=15.5 Hz, 1H), 3.83-3.81 (m, 1H), 3.71 (s, 3H), 3.48-3.38(m, 1H), 2.26 (td, J=8.8, 6.2 Hz, 1H), 2.19 (td, J=13.3, 11.1 Hz, 1H),2.02-1.10 (comp, 19H), 1.08 (d, J=6.6 Hz, 3H), 0.98-0.91 (m, 1H), 0.89(s, 3H), 0.87 (s, 9H), 0.68 (s, 3H), 0.04 (s, 6H).

Example 6. Preparation of Compound (II) from Compound 6

To a solution of compound 6 (41.3 g, 80.0 mmol, 1.0 eq) in EtOAc (227mL, 5.4v) and CH₃CN (227 mL, 5.4v) was added a solution of K₂CO₃ (110 g,796 mmol, 10.0 eq) in H₂O (341 mL, 8.3v). RuCl₃ hydrate (0.90 g, 4.0mmol, 0.05 eq) was added, followed by NaIO₄ (170 g, 796 mmol, 10.0 eq)and the reaction was stirred vigorously o/n until no starting materialremains by HPLC. The reaction mixture was filtered and the solid wasrinsed with EtOAc. The filtrate was quenched with aqueous 10% citricacid (600 mL). The layers were separated and the aqueous layer wasextracted with EtOAc (250 mL). The combined organic layers were washedwith water (2×400 mL), brine (400 mL), dried (Na₂SO₄) and concentratedto about 400 mL. About 400 mL of heptane was added and the mixture wasconcentrated under reduced pressure slowly at 38° C. to reduce the totalvolume to about 100 mL. The resultant mixture was cooled to roomtemperature and filtered to collect the solid, rinsing with hexanes.This crystallization procedure was repeated once to produce a second lotof material. In total compound (III) (12.0 g, 25.1 mmol, 76% yield) as atan solid. ¹H NMR (400 MHz, Chloroform-d) δ 3.56 (tt, J=10.4, 4.7 Hz,1H), 2.82 (dd, J=12.3, 5.7 Hz, 1H), 2.45-2.39 (m, 1H), 2.39-2.32 (m,1H), 2.27 (dtt, J=10.1, 7.2, 3.6 Hz, 1H), 1.99-1.75 (m, 5H), 1.67-1.25(comp, 11H), 1.23 (d, J=6.8 Hz, 3H), 1.17 (s, 3H), 1.16-1.07 (m, 1H),0.99 (qd, J=12.1, 6.3 Hz, 1H), 0.86 (s, 9H), 0.67 (s, 3H), 0.03 (s, 6H).

Example 7. Preparation of Compound 8 from Compound (III)

Isobutyl chloroformate (10.51 mL, 81 mmol) was added dropwise to asolution of compound (III) (32.2 g, 67.5 mmol) and Et₃N (14.12 mL, 101mmol) in DCM (225 mL) at 0° C. The reaction was stirred at 0° C. for 30min. Reaction diluted with MBTE (500 mL), washed with water (2×500 mL),brine (500 mL), dried (MgSO₄) and concentrated to give compound 8 as anorange gum, which was directly used in the next step. ¹H NMR (400 MHz,Chloroform-d) δ 4.04 (d, J=6.7 Hz, 2H), 3.55 (tt, J=10.4, 4.7 Hz, 1H),2.82 (dd, J=12.6, 6.0 Hz, 1H), 2.50 (dq, J=10.3, 6.8 Hz, 1H), 2.36 (t,J=11.3 Hz, 1H), 2.27 (dddd, J=12.9, 10.1, 7.1, 3.2 Hz, 1H), 2.11-1.32(comp, 15H), 1.31-1.24 (m, 1H), 1.28 (d, J=6.9 Hz, 3H), 1.18 (s, 3H),1.17-1.09 (m, 1H), 1.07-0.99 (m, 1H), 1.00-0.94 (m, 1H), 0.97 (d, J=6.7Hz, 6H), 0.86 (s, 9H), 0.68 (s, 3H), 0.03 (s, 6H).

Example 8. Preparation of Compound (IV) from Compound 8

NaBH₄ (5.11 g, 135 mmol) was added to a solution of compound 8 (38.9 g,67.5 mmol) in THF (270 ml)/H₂O (67.5 ml) at 0° C. The reaction wasstirred at 0° C. for 0.5 h and a second portion of NaBH₄ (5.11 g, 135mmol) was added. The reaction was stirred overnight, warming slowly tort. Reaction complete by TLC and HPLC. The reaction was cooled to 0° C.,diluted with EtOAc (300 mL) and quenched with 10% citric acid (300 mL).The layers were separated and the aqueous layer extracted with EtOAc(2×150 mL). The combined organic layers were washed with brine (300 mL),dried (MgSO₄), filtered, and concentrated to give the crude productwhich was purified by column chromatography eluting with hexanes/acetone(0% acetone→25% acetone, 330 g column) to give compound (IV) (26.2 g,56.4 mmol, 84% yield) as a colorless amorphous solid. ¹H NMR (400 MHz,Chloroform-d) δ 3.83 (q, J=3.1 Hz, 1H), 3.64 (dd, J=10.4, 3.3 Hz, 1H),3.48-3.38 (m, 1H), 3.35 (dd, J=10.5, 7.1 Hz, 1H), 2.19 (td, J=13.3, 11.0Hz, 1H), 2.03-1.73 (comp, 5H), 1.72-1.08 (comp, 15H), 1.04 (d, J=6.6 Hz,3H), 0.94 (td, J=14.5, 3.3 Hz, 1H), 0.89 (s, 3H), 0.88 (s, 9H), 0.67 (s,3H), 0.04 (s, 6H).

Example 9. Synthesis of Compound 15D

To a suspension of 2,2-dimethylchromane-6-sulfonamide (65 g, 269 mmol,1.0 eq) and Et₃N (82 g, 113 mL, 808 mmol, 3.0 eq) in anhydrous CH₂Cl₂(673 mL, 10v) at 0° C. was charged PhOCOCl (50.6 g, 40.6 mL, 323 mmol,1.2 eq). The reaction was stirred at 0° C. for 3 hrs. Upon completion,the reaction was diluted with CH₂Cl₂ (400 mL). The mixture was washedwith cold H₂O (1000 mL), cold aqueous 10% citric acid (2×500 mL), andbrine (1000 mL). The organic layer was dried (Na₂SO₄), filtered, andconcentrated to about 500 mL total volume. Hexanes (500 mL) was addedand the solution was concentrated to about 250 mL total volume. Themixture was cooled to rt. The resultant precipitate was collected byfiltration, rinsing with hexanes (3×100 mL), and dried under vacuum togive compound 15D (72.5 g, HPLC, ELSD purity: 98.8%, HPLC UV₂₄₀ purity:85.7%) as a tan solid. ¹H NMR (400 MHz, Chloroform-d) δ 7.85-7.74 (m,2H), 7.58 (s, 1H), 7.40-7.29 (m, 2H), 7.27-7.18 (m, 1H), 7.11-7.02 (m,2H), 6.86 (t, J=8.6 Hz, 1H), 2.82 (t, J=6.7 Hz, 2H), 1.84 (t, J=6.7 Hz,2H), 1.36 (d, J=2.1 Hz, 6H).

Example 10. Preparation of Compound 17 from Compound (IV)

Compound 15D (17.46 g, 48.3 mmol) was added to a solution of compound(IV) (21.8 g, 46.9 mmol) and triethylamine (19.61 ml, 141 mmol) in dryTHE (188 mL) at rt. The reaction mixture started at a clear solution.After about a hour, lots of solid precipitation formed. After stirringat rt for 2 hours, the reaction mixture was diluted with MTBE (150 mL)and stirred at 35° C. for 45 mins to allow the solid precipitate to age.Then the slurry mixture was concentrated slowly under reduced vacuum toremove −80 mL of the solvent. The remaining solution with solidprecipitate was cooled down to rt slowly and aged overnight. The solidwas then collected by filtration, rinsed with MTBE, and dried under highvacuum to provide ˜30 g of nice solid compound 17 as the NEt₃ salt form.The obtained compound 17, NEt₃ salt (˜30 g) was partitioned in EtOAc 500mL/10% citric acid (300 mL). The organic layer was separated and washedwith water, sat. NaHCO₃, brine dried and concentrated to afford compound17 (27.7 g, 87% yield). ¹H NMR (400 MHz, Chloroform-d) δ 7.75-7.64 (m,2H), 7.36 (s, 1H), 6.82 (d, J=8.6 Hz, 1H), 4.08 (m, 1H), 3.81-3.68 (m,2H), 3.39 (m, 1H), 2.79 (t, J=6.7 Hz, 2H), 2.14 (td, J=13.2, 11.1 Hz,1H), 1.97-1.67 (m, 6H), 1.67-1.32 (m, 10H), 1.31 (s, 6H), 1.31-0.99 (m,6H), 0.97-0.87 (m, 4H), 0.84 (s, 12H), 0.60 (s, 3H), 0.00 (s, 6H).

Example 11. Preparation of Compound (VII) from Compound 17

A premixed solution of conc. HCl (294 mg, 2.98 mmol) in MeOH (5 mL) wasadded dropwise to a solution of compound 17 (21.84 g, 29.8 mmol) in MeOH(120 mL) at rt. The reaction was stirred at rt for ˜30 min and monitoredby TCL and HPCL. Upon completion, a solution of 50% NaOH (239 mg, 2.98mmol) in water (1 mL) was added and the reaction mixture wasconcentrated to dryness. The crude solid was purified by silica gelchromatography with (220 g SiO₂, 100% hexanes to 50% acetone/hexanes,product came out around 50% acetone/hexanes) to give compound (VII) (15g, 81% yield). LC-MS (m/z, ES⁻): 616.33 [M−1]. H NMR (400 MHz,Chloroform-d) δ 7.79-7.68 (m, 2H), 7.32 (s, 1H), 6.87 (d, J=8.7 Hz, 1H),4.12 (dd, J=10.5, 3.3 Hz, 1H), 3.87-3.74 (m, 2H), 3.48 (m, 1H), 2.83 (t,J=6.7 Hz, 2H), 2.28-2.13 (m, 1H), 2.04-1.89 (m, 2H), 1.88-1.79 (m, 4H),1.78-1.59 (m, 4H), 1.55 (s, 3H), 1.48-1.36 (m, 3H), 1.36 (s, 6H),1.37-1.23 (m, 3H), 1.25-1.06 (m, 3H), 1.05-0.92 (m, 4H), 0.90 (s, 3H),0.65 (s, 3H).

Example 12. Preparation of Compound 9 from Compound (III)

To a suspension of compound (III) (15.2 g, 31.9 mmol, 1.0 eq) in MeOH(91 mL, 6v) at 0° C. was charged AcCl (12.5 g, 11.3 mL, 159 mmol, 5.0eq) dropwise. The resulting solution was heated at 50° C. for 24 hrs.The reaction was concentrated and the resultant brown solid waspartitioned between EtOAc (250 mL) and sat. aqueous NaHCO₃ (250 mL). Thelayers were separated and the organic layer was washed with H₂O (200 mL)and brine (200 mL). The organic layer was dried (MgSO₄), filtered, andconcentrated to about 100 mL. Hexanes (150 mL) was added and the mixtureconcentrated at 40° C. to about 100 mL total volume. The resultingsuspension was cooled to room temperature and allowed to age o/n. Theprecipitate was filtered, rinsing with hexanes, to give compound 9 (8.9g, 23.6 mmol, 74% yield) as a colorless solid. ¹H NMR (500 MHz,Chloroform-d) δ 3.65 (s, 3H), 3.67-3.58 (m, 1H), 2.85 (ddd, J=12.7, 6.1,1.1 Hz, 1H), 2.48-2.33 (m, 2H), 2.22 (dddd, J=13.0, 10.2, 7.2, 3.3 Hz,1H), 2.01-1.66 (m, 7H), 1.66-1.53 (m, 3H), 1.54-1.45 (m, 3H), 1.45-1.11(m, 10H), 1.04-0.92 (m, 1H), 0.92-0.80 (m, 1H), 0.67 (s, 3H).

Example 13. Preparation of Compound 10 from Compound 9

To a solution of compound 9 (8.7 g, 23.1 mmol, 1.0 eq) and Et₃N (18.7 g,25.8 mL, 185 mmol, 8.0 eq) in DCM (154 mL, 17v) at 0° C. was chargedTMSOTf (25.7 g, 20.9 mL, 116 mmol, 5.0 eq) dropwise. The reaction wasstirred for 1 hr at 0° C. then poured into cold sat. aqueous NaHCO₃ (300mL) and diluted with DCM (150 mL). The layers were separated and theorganic layer was washed with water (2×150 mL) and brine (150 mL), dried(MgSO₄), filtered, and concentrated under reduced pressure. Theresultant residue was partitioned between hexanes (300 mL) and water(150 mL). The layers were separated and the organic layer was washedwith brine (150 mL), dried (MgSO₄), filtered, and concentrated to givecrude compound 10 (11.1 g) as a colorless amorphous solid. This materialwas used in the next step without further purification. The CDCl₃ usedfor H-NMR was be pre-treated with K₂CO₃ to avoid acid-mediateddecomposition of compound 10. ¹H NMR (400 MHz, Chloroform-d) δ 4.61 (dd,J=5.9, 1.9 Hz, 1H), 3.53 (s, 3H), 3.44-3.35 (m, 1H), 2.31 (dq, J=10.2,6.9 Hz, 1H), 1.88-1.75 (m, 3H), 1.73-1.64 (m, 2H), 1.62-1.50 (m, 3H),1.48-1.37 (m, 3H), 1.37-1.02 (m, 7H), 1.08 (d, J=6.8 Hz, 3H), 0.94 (td,J=14.2, 3.2 Hz, 1H), 0.72 (s, 3H), 0.58 (s, 3H), 0.04 (s, 9H), −0.00 (s,9H).

Example 14. Preparation of Compound 11 from Compound 10

To a solution of compound 10 (11.1 g, 21.3 mmol, 1.0 eq) andacetaldehyde (2.3 g, 3.0 mL, 53.3 mmol, 2.5 eq) in DCM (107 mL, 10v) at−78° C. was charged BF₃.OEt₂ (13.2 mL, 107 mmol, 5.0 eq) dropwise. Thereaction was stirred at −78° C. for 4 hrs, whereupon MeOH (40 mL) wasadded dropwise. The reaction was warmed to room temperature and stirredo/n. The reaction was cooled to 0° C. and carefully quenched withaqueous sat. NaHCO₃ (250 mL) and diluted with DCM (150 mL). The layerswere separated and the aqueous layer was extracted with DCM (1×150 mL).The combined organic layers were washed with brine (250 mL), dried(MgSO₄), filtered, and concentrated to give crude compound 11 (8.7 g,HPLC purity: 98.7%, mixture of E/Z isomers) as a yellow amorphous solid.This material was used in the next step without further purification.LC-MS (m/z, ES⁺): 403.29 [M+H].

Example 15. Preparation of Compound 12 from Compound 11

To a solution of crude compound 11 (8.6 g, 21.3 mmol, 1.0 eq) in MeOH(71 mL, 12.4v) was charged 10% Pd/C (50% H₂O, 2.3 g, 0.25 wt). Thereaction was evacuated and backfilled with H₂ (3×). The reaction wasstirred for 72 hrs, diluted with EtOAc, and filtered through CELITE©.The filtrate was concentrated to give crude compound 12 (8.1 g, HPLCpurity: 98.0%) as a colorless amorphous solid. This material was used inthe next step without further purification. ¹H NMR (400 MHz,Chloroform-d) δ 3.58 (s, 3H), 3.53-3.47 (m, 1H), 2.49 (dd, J=12.0, 10.7Hz, 1H), 2.35 (dq, J=10.4, 6.8 Hz, 1H), 2.19-2.04 (m, 1H), 1.93-1.79 (m,3H), 1.79-1.64 (m, 4H), 1.64-1.54 (m, 3H), 1.53-1.35 (m, 4H), 1.32-1.15(m, 3H), 1.15 (s, 3H), 1.13 (q, J=7.2 Hz, 2H), 0.92-0.82 (m, 1H), 0.78(t, J=7.2 Hz, 3H), 0.61 (s, 3H).

Example 16. Preparation of Compound 13 from Compound 12

To a solution of crude compound 12 (8.0 g, 19.8 mmol, 1.0 eq) in MeOH(99 mL, 12.3v) and H₂O (24.7 mL, 3.1v) was charged 50% aqueous NaOH (7.9mL, 98.9 mmol, 5.0 eq) and the reaction was stirred at 60° C. for 24hrs. The reaction was cooled to 0° C. and made acidic (pH ˜1-2) with 1MHCl. The aqueous mixture was extracted with EtOAc (3×200 mL). Thecombined organic layers were dried (MgSO₄), filtered, and concentratedto give crude compound 13 (7.5 g, HPLC purity: 98.0%) as a pale yellowamorphous solid. This material was used in the next step without furtherpurification. ¹H NMR (400 MHz, Chloroform-d) δ 3.45-3.36 (m, 1H), 2.55(q, J=6.2 Hz, 1H), 2.34-2.16 (m, 1H), 2.14-2.05 (m, 1H), 1.85-1.52 (m,8H), 1.36 (dddt, J=23.7, 9.8, 5.5, 3.3 Hz, 3H), 1.29-1.18 (m, 1H),1.17-1.06 (m, 9H), 1.06-0.91 (m, 2H), 0.90-0.72 (m, 2H), 0.66 (t, J=7.4Hz, 3H), 0.54 (s, 3H).

Example 17. Preparation of Compound (V) from Compound 13

To a solution of crude compound 13 (7.7 g, 19.8 mmol, 1.0 eq) in THE(65.9 mL, 8.5v) and DMF (16.5 mL, 2.1v) at 0° C. was charged imidazole(8.1 g, 119 mmol, 6.0 eq) and TBSCl (6.6 g, 43.5 mmol, 2.2 eq). The icebath was removed, and the reaction was stirred at room temperature for18 hrs. Methanol (16.5 mL, 2.1v) and K₂CO₃ (1.4 g, 9.9 mmol, 0.5 eq)were added and the reaction was stirred for 2 hrs. The reaction wascarefully acidified with 10% aqueous citric acid (200 mL) and dilutedwith EtOAc (200 mL). The layers were separated and the aqueous layer wasextracted with EtOAc (2×200 mL). The combined organic layers were washedwith H₂O (3×100 mL) and brine (100 mL), then dried (MgSO₄), filtered,and concentrated to give a yellow solid. This solid was recrystallizedfrom CH₂Cl₂/hexanes to give compound (V) (7.1 g, 71% yield over 5 stepsHPLC purity: 98.2%). ¹H NMR (500 MHz, Chloroform-d) δ 9.78 (bs, 1H),3.50-3.43 (m, 1H), 2.63 (q, J=6.3 Hz, 1H), 2.41-2.34 (m, 1H), 2.26-2.19(m, 1H), 1.91-1.82 (m, 3H), 1.81-1.65 (m, 3H), 1.64-1.27 (m, 8H),1.25-1.16 (7H), 1.14-1.07 (m, 2H), 1.01-0.86 (m, 3H), 0.83 (s, 9H), 0.78(t, J=7.4 Hz, 3H), 0.65 (s, 3H), −0.00 (s, 6H).

Example 18. Preparation of Compound 15 from Compound (V)

To a solution of compound (V) (7.1 g, 14.1 mmol, 1.0 eq) in DCM (46.9mL, 6.6v) at 0° C. was charged Et₃N (2.1 g, 2.9 mL, 21.1 mmol, 1.5 eq)and isobutyl chloroformate (2.3 g, 2.2 mL, 16.9 mmol, 1.2 eq) and thereaction was stirred for 30 min at 0° C. The reaction was diluted withMBTE (150 mL) and washed with water (2×100 mL), brine (100 mL), dried(MgSO₄) and concentrated to give crude compound 15 (9.0 g, HPLC purity:99.1%) as an orange amorphous solid. The crude sample was used directlyin the next step without further purification.

Example 19. Preparation of Compound (VI) from Compound 15

To a solution of crude compound 15 (8.5 g, 14.1 mmol, 1.0 eq) in THE (47mL, 5.5v) and H₂O (23 mL, 2.7v) at 0° C. was charged NaBH₄ (1.1 g, 28.1mmol, 2.0 eq) and the reaction was stirred for 30 min at 0° C. NaBH₄(1.1 g, 28.1 mmol, 2.0 eq) was added and the reaction was stirredovernight, warming slowly to rt. The reaction was cooled to 0° C.,diluted with EtOAc (85 mL) and quenched carefully with 10% citric acid(85 mL). The layers were separated and the aqueous layer was extractedwith EtOAc (2×40 mL). The combined organic layers were dried (MgSO₄),filtered, and concentrated to give crude compound (VI) (6.9 g, HPLCpurity: 95.8%) as a pale yellow amorphous solid. ¹H NMR (400 MHz,Chloroform-d) δ 3.71-3.52 (m, 2H), 3.44-3.20 (m, 2H), 1.91 (dt, J=12.3,2.9 Hz, 1H), 1.76 (dtd, J=20.6, 10.0, 4.5 Hz, 4H), 1.62 (ddp, J=9.8,6.8, 3.8, 3.0 Hz, 2H), 1.58-1.27 (m, 8H), 1.27-1.05 (m, 5H), 1.00 (d,J=6.6 Hz, 2H), 0.94 (dd, J=14.3, 3.6 Hz, 1H), 0.90-0.85 (m, 4H), 0.84(s, 9H), 0.63 (s, 3H), −0.00 (s, 6H).

Example 20. Preparation of Compound 18b from Compound (VIb)

To a stirred solution of (VIb) (22.33 g, 39.5 mmol) and 15D (20 g, 55.3mmol) in THE (180 mL) at RT was added TEA (8.26 ml, 59.3 mmol), followedby DMAP (0.966 g, 7.91 mmol). The resulting mixture was heated to 50° C.and stirred for 2 h at 50° C., cooled down to RT, quenched with 3%citric acid, and extracted with EtOAc. The combined organic layers werewashed with brine and concentrated in vacuo, and the residue waspurified by chromatography on silica gel using hexane/EtOAc (100/0 to70/30, 15 min) to give a product as a white foam. 32.2 g of compound18b. ¹H NMR (500 MHz, Chloroform-d) δ 7.71-7.61 (m, 2H), 7.19-7.16 (m,1H), 6.83-6.72 (m, 1H), 4.06 (dd, J=10.3, 3.4 Hz, 1H), 3.65 (dd, J=10.5,8.1 Hz, 1H), 3.56 (s, 1H), 3.26 (dt, J=10.9, 6.7 Hz, 1H), 2.75 (t, J=6.7Hz, 2H), 1.88-1.70 (m, 5H), 1.74-1.46 (m, 4H), 1.46-1.36 (m, 4H),1.35-1.13 (m, 12H), 1.09 (m, 4H), 0.99-0.91 (m, 2H), 0.95-0.76 (m, 9H),0.92-0.74 (m, 21H), 0.81 (s, 9H), 0.54 (s, 3H), 0.00 (s, 9H), −0.03 (s,6H).

Example 21. Preparation of Compound (VIII) from Compound 18b

To a stirred solution of 18b (32 g, 38.4 mmol) in MeOH (180 ml) at RTwas added HCl (0.316 ml, 3.84 mmol). The mixture was stirred at RT for 1h, and then quenched with 0.6 ml of 6N NaOH and concentrated in vacuo.The residue was purified by chromatography on silica gel usinghexane/acetone (100/0 to 50/50, 20 min) to give compound (VIII) as awhite solid (21 g, 85%). LC-MS (m/z, ES⁻): 644.36 [M−1]. ¹H NMR (400MHz, Chloroform-d) δ 7.71-7.55 (m, 3H), 6.79 (d, J=8.7 Hz, 1H), 4.04(dd, J=10.4, 3.3 Hz, 1H), 3.76-3.57 (m, 2H), 3.34 (tt, J=10.5, 5.1 Hz,1H), 2.75 (t, J=6.7 Hz, 2H), 1.88-1.70 (m, 5H), 1.74-1.46 (m, 4H),1.46-1.36 (m, 4H), 1.35-1.13 (m, 12H), 1.09 (m, 4H), 0.99-0.91 (m, 2H),0.95-0.76 (m, 9H), 0.57 (s, 3H).

Example 22. Synthesis of 20A

A solution of 6-chloropyridine-3-sulfonyl chloride (50 g) in MeCN (75ml) was added dropwise to aq NH₄OH (28-30%, 125 ml) at 0° C. (ice bath)(exthothermic). After addition, the ice bath was removed and thereaction mixture was stirred for another 45 min, and then cooled down to0° C. again, quenched with water and acidified with 37% HCl (120 ml) topH 1-2. The mixture was extracted with EtOAc, and the combined organiclayers were washed with brine, dried over Na₂SO₄, filtered, andconcentrated. The crude product (40 g) was dried overnight under highvacuum and used directly for the next step.

The crude product, 6-chloropyridine-3-sulfonamide (79 g), was firstsuspended in EtOH (560 ml), and then piperidine (85 ml) was addedslowly. The resulting mixture was refluxed for 22 h, cooled down to rt,and the precipitated solids (after 3 h aging) were collected byfiltration and rinsed with EtOH, and dried. The solids were furtherpurified by mixing with water, filtration, and washing with water, andthen dried to give compound 20A as a white solid (94 g, 95% yield). ¹HNMR (400 MHz, DMSO-d₆) δ 8.42 (d, J=2.5 Hz, 1H), 7.79 (dd, J=9.2, 2.6Hz, 1H), 7.15 (s, 2H), 6.91 (d, J=9.1 Hz, 1H), 3.64 (dd, J=6.5, 4.4 Hz,4H), 1.64 (qd, J=6.2, 5.8, 3.4 Hz, 2H), 1.53 (tq, J=7.9, 4.8, 4.1 Hz,4H).

Example 23. Preparation of Compound 20D from 20A

Phenyl chloroformate (24.95 ml, 199 mmol) was added dropwise to asuspension of 20A (40 g, 166 mmol) and TEA (69.3 ml, 497 mmol) in DCM(400 ml) at 0° C. The suspension slowly became clear during the additionof phenyl chloroformate (about half way) then cloudy again. The reactionmixture was stirred at 0° C. for 2 h, then diluted with DCM (700 mL),washed with water (2×700 mL) and 10% citric acid (2×400 ml), the organiclayer was separated quickly (precipitation formed quickly after secondwash with 10% citric acid) and the formed solids (after 30 min aging)were filtered off and rinsed with DCM, and dried to give 29 g ofcompound 20D. The filtrate was concentrated to 200 mL and the solidswere filtered and rinsed with DCM, and dried to afford another 19 g ofcompound 20D (48 g in total, 80% yield). ¹H NMR (400 MHz, Chloroform-d)δ 8.71 (dd, J=2.6, 0.7 Hz, 1H), 7.96 (dd, J=9.3, 2.6 Hz, 1H), 7.66 (s,1H), 7.40-7.30 (m, 2H), 7.27-7.18 (m, 1H), 7.13-7.05 (m, 2H), 6.58 (dd,J=9.4, 0.7 Hz, 1H), 3.70 (t, J=5.4 Hz, 4H), 1.77-1.59 (m, 6H).

Example 24. Preparation of Compound 19b from Compound (VIb)

To a solution of 20D (22.83 g, 63.2 mmol) in THE (354 mL) at rt wasadded compound (VIb) (34 g, 60.2 mmol), triethylamine (25.2 ml, 181mmol), and DMAP (0.735 g, 6.02 mmol). The resulting slurry was heated to50° C. and stirred for 4 hrs (the mixture was almost clear), then cooleddown to rt, and diluted with EtOAc (1000 mL). The mixture was washedwith 3% citric acid and brine, dried over Na₂SO₄, and concentrated. Theresidue was purified by chromatography on silica gel usinghexane/acetone (100/0 to 65/35, 25 min) to give compound 19b (49 g, 93%yield) as a white foam containing a small amount of phenol (sideproduct). ¹H NMR (400 MHz, Chloroform-d) δ 8.62 (d, J=2.5 Hz, 1H),7.99-7.94 (m, 1H), 7.19-7.14 (m, 1H), 6.62 (d, J=9.4 Hz, 1H), 4.08 (dd,J=10.4, 3.6 Hz, 1H), 3.69 (s, 3H), 3.73-3.61 (m, 1H), 3.56 (d, J=2.6 Hz,1H), 3.51 (s, 1H), 3.27 (td, J=10.8, 5.3 Hz, 1H), 1.94-1.58 (m, 12H),1.54-1.45 (m, 2H), 1.44 (s, 1H), 1.38 (s, 1H), 1.39-1.25 (m, 2H),1.28-1.11 (m, 3H), 1.14-0.93 (m, 3H), 0.97-0.84 (m, 4H), 0.79 (d, J=10.3Hz, 16H), 0.78-0.74 (m, 6H), 0.57 (d, J=11.6 Hz, 1H), 0.55 (s, 2H), 0.00(s, 9H), −0.03 (s, 6H).

Example 25. Preparation of Compound (IX) from Compound 19b

To a solution of 19b (49 g, 58.9 mmol) in MeOH (294 ml) at rt was addedHCl (37%) (1.450 ml, 17.66 mmol). The resulting mixture was stirred for3 h, then neutralized with sodium hydroxide (50%) (0.933 ml, 17.66 mmol)in 2 ml of water, and concentrated. The residue was purified bychromatography on silica gel using hexane/acetone (100/0 to 50/50, 15min) to give a product as a white foam, which was chased 3 times withethanol to remove the residual acetone. The resulting white foam waslyophilized for 7 days to afford compound (IX) (32 g, 84%). LC-MS (m/z,ES⁺): 646.39 [M+1]. ¹H NMR (400 MHz, DMSO-d₆) δ 11.70 (s, 1H), 8.46 (d,J=2.6 Hz, 1H), 7.78 (dd, J=9.3, 2.7 Hz, 1H), 6.93 (d, J=9.3 Hz, 1H),4.33 (d, J=18.4 Hz, 1H), 4.05 (d, J=5.1 Hz, 1H), 3.98 (dd, J=10.6, 3.4Hz, 1H), 3.74 (dd, J=10.6, 7.0 Hz, 1H), 3.68 (t, J=5.5 Hz, 4H),3.52-3.41 (m, 2H), 3.14 (s, 1H), 1.89-1.74 (m, 2H), 1.74-1.60 (m, 6H),1.61-1.51 (m, 6H), 1.44 (td, J=14.7, 8.4 Hz, 4H), 1.41-1.25 (m, 2H),1.28-1.00 (m, 7H), 1.02-0.88 (m, 2H), 0.92-0.79 (m, 9H), 0.59 (s, 3H).

While this invention has been particularly shown and described withreferences to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the scope of the inventionencompassed by the appended claims.

What is claimed is:
 1. A process for preparing a compound of Formula(I):

wherein R¹ is selected from the group consisting of: 1) substituted orunsubstituted —C₁-C₈ alkyl; 2) substituted or unsubstituted —C₂-C₈alkenyl; 3) substituted or unsubstituted —C₂-C₈ alkynyl; 4) substitutedor unsubstituted —C₃-C₈ cycloalkyl; 5) substituted or unsubstitutedaryl; 6) substituted or unsubstituted arylalkyl; 7) substituted orunsubstituted 3- to 12-membered heterocycloalkyl; 8) substituted orunsubstituted heteroaryl; 9) substituted or unsubstitutedheteroarylalkyl; and 10) NR_(a)R_(b); wherein, R_(a) and R_(b) are eachindependently selected from hydrogen, substituted or unsubstituted—C₁-C₈ alkyl, substituted or unsubstituted —C₂-C₈ alkenyl, substitutedor unsubstituted —C₂-C₈ alkynyl, substituted or unsubstituted —C₃-C₈cycloalkyl; Alternatively R_(a) and R_(b) are taken together with thenitrogen atom to which they are attached to form a 3- to 12-memberedheterocyclic ring; said process comprising the steps of: (1) reacting acompound of Formula (IV),

wherein PG is a hydroxyl protecting group; with a compound of Formula15E,

wherein R⁴ is imidazol-1-yl, alkyl-O—, aryl-O, Cl, or —CCl₃, in thepresence of an organic base, to produce a compound of Formula 14,

and (2) deprotecting the compound of Formula 14 to produce the compoundof Formula I.
 2. The process of claim 1, wherein R₁ is


3. The process of claim 1, wherein R₁ is


4. The process of claim 1, wherein R⁴ is imidazol-1-yl, MeO—, EtO— orPhO—.
 5. The process of claim 2, wherein the compound of Formula 15E iscompound 15B or 15C:

wherein R⁵ is alkyl or aryl.
 6. The process of claim 5, wherein thecompound of Formula 15E is compound 15C wherein R⁵ is phenyl.
 7. Theprocess of claim 3, wherein the compound of Formula 15E is compound 20Bor 20C,

wherein R⁵ is alkyl or aryl.
 8. The process of claim 7, wherein thecompound of Formula 15E is compound 15C wherein R⁵ is phenyl.
 9. Theprocess of claim 1, wherein PG is tert-butyl dimethylsilyl.
 10. Theprocess of claim 1, wherein step (1) is carried out in an aproticsolvent.
 11. The process of claim 10, wherein the aprotic solvent istetrahydrofuran, dichloromethane or toluene.
 12. The process of claim 1,wherein the base is trimethylamine or diisopropylethylamine.